Catalyst 9300 を2台の独立した装置として動かし、下流の1つの LACP EtherChannel を両方に接続する BGP EVPN All-Active Multihoming を構成しました。
本記事では、non-fabric 構成の実機設定と、制御プレーン・転送テーブル・LACP・DF を順番に確認する方法をまとめます。

確認日は 2026年10月20日。装置間は L3 EtherChannel Po48 で接続し、BFD を使用しない基本構成で IS-IS・EVPN・BGP の fall-over host-route・core-tracking を確認しています。後半には Po48 の片系・両系停止と自動復旧、および BFD を使用する場合のタイマー制約と検証結果を掲載します。

設定とコマンド出力は折りたたんであります。各項目を開くと確認できます。
IP アドレスはラボの値です。hostname は記事用に C9300-1／C9300-2 に統一し、実機の hostname 自体は変更していません。公開用に MAC と、それから生成される ESI／ES-Import 値を整合させて置き換えています。装置シリアル、認証情報、クラウド管理設定は掲載していません。数値・時刻・経路件数は採取時点の値です。show 出力は関連行を抜粋し、メモリ使用量や重複する凡例などを省いています。

1. 使用機器と構成の位置付け

項目	#1	#2
hostname	C9300-1	C9300-2
実際のモデル	C9300-48P	C9300-48P
IOS XE	26.2.1（実機表示 26.02.01）	同左
接続先 IP	192.168.32.2	192.168.32.3
ライセンス使用状態	network-advantage / dna-advantage: IN USE	同左
underlay	IS-IS Level-2、L3 Po48（Gi47＋Gi48）	同左
overlay 制御	Loopback0 間の iBGP、AS 65100	同左
ES アクセスポート	Gi1/0/36 → Po36	Gi1/0/36 → Po36
Anycast Gateway	VLAN 100・101 の SVI、GRT	同左

モデルは両方とも C9300-48P、検証バージョンは IOS XE 26.2.1 です。

本記事では、EVPN を終端する C9300 を PE、下流の接続装置を CE と呼びます。Ethernet Segment（ES） は、CE とそれを収容する PE 群を結ぶリンクの集合です。今回の Po36 は、2台の PE が同じ ESI で識別する1つの ES を構成します。RFC 7432

Cisco の Non-Fabric Networks 設定ガイドをベースにしています。本記事で扱う non-fabric EVPN Multihoming について、ガイドには IOS XE 17.18.2 以降の対応情報と Controlled Availability の条件が掲載されています。採用時は対象モデル・リリースの対応条件を確認してください。
26.2.1 の表記と機能追加は Catalyst 9300 リリースノートでも確認できます。

機種・バージョン・ライセンスの実機確認

機種・バージョン・ライセンスの実機確認.txt

C9300-1#show version
Cisco IOS XE Software, Version 26.02.01
Cisco IOS Software [IOSXE], Catalyst L3 Switch Software (CAT9K_IOSXE), Version 26.02.1, RELEASE SOFTWARE (fc3)
------------------------------------------------------------------------------
------------------------------------------------------------------------------
network-advantage   	Smart License                 	 network-advantage
dna-advantage       	Subscription Smart License    	 dna-advantage
Model Number                       : C9300-48P
------ ----- -----              ----------        ----------            ----
*    1 65    C9300-48P          26.02.01          CAT9K_IOSXE           INSTALL
C9300-1#

C9300-1#show license summary
  -----------------------------------------------------------------------------
  network-advantage       (C9300-48 Network Advan...)       1 IN USE
  dna-advantage           (C9300-48 DNA Advantage)          1 IN USE
C9300-1#

C9300-1#show switch
Switch#   Role    Mac Address     Priority Version  State
-------------------------------------------------------------------------------------
*1       Active   0200.0000.0099     1      V01     Ready
C9300-1#

C9300-1#show system mtu
Global Ethernet MTU is 9100 bytes.
C9300-1#

C9300-2#show version
Cisco IOS XE Software, Version 26.02.01
Cisco IOS Software [IOSXE], Catalyst L3 Switch Software (CAT9K_IOSXE), Version 26.02.1, RELEASE SOFTWARE (fc3)
------------------------------------------------------------------------------
------------------------------------------------------------------------------
network-advantage   	Smart License                 	 network-advantage
dna-advantage       	Subscription Smart License    	 dna-advantage
Model Number                       : C9300-48P
------ ----- -----              ----------        ----------            ----
*    1 65    C9300-48P          26.02.01          CAT9K_IOSXE           INSTALL
C9300-2#

C9300-2#show license summary
  -----------------------------------------------------------------------------
  network-advantage       (C9300-48 Network Advan...)       1 IN USE
  dna-advantage           (C9300-48 DNA Advantage)          1 IN USE
C9300-2#

C9300-2#show switch
Switch#   Role    Mac Address     Priority Version  State
-------------------------------------------------------------------------------------
*1       Active   0200.0000.0080     1      V01     Ready
C9300-2#

C9300-2#show system mtu
Global Ethernet MTU is 9100 bytes.
C9300-2#

2. 論理構成と実験用の実配線

2.1 通常の構成イメージ

Cisco の non-fabric の基本設定例に合わせ、inter-ES 接続を L3 EtherChannel Po48 にまとめました。Gi47／Gi48 は no switchport の LACP メンバーで、IP アドレス・IS-IS・core-tracking は論理インターフェイス Po48 に設定します。

IPv4 IGP は IS-IS を選択しています。対向 Loopback0 の /32 は Po48 経由の1経路となり、2本の物理リンクへの振り分けは EtherChannel のハッシュが担います。独立した L3 リンク2本による ECMP ではありません。その上に EVPN iBGP と VXLAN の到達性を用意します。spine／route reflector は置いていません。

2.2 今回は #1 の別 VRF を CE 代わりに使用

独立した3台目の CE は使わず、#1 の Po99 を TEST-CE VRF に入れて疑似 CE としています。

接続元	接続先	役割
#1 Gi1/0/33（Po99）	#2 Gi1/0/36（Po36）	CE から #2 へのリンク
#1 Gi1/0/34（Po99）	#1 Gi1/0/36（Po36）	CE から #1 へのリンク。同一筐体内の折り返し配線
#1 Po99	TEST-CE: 192.168.33.2/24	送信元端末の代用

Po99 は L3 EtherChannel。Po36 の native VLAN 100 に対して untagged の IPv4 トラフィックを送れます。TEST-CE のデフォルトルートは 192.168.33.1 です。
この方法で VLAN 100 の疎通と ES アクセスリンク障害を試せます。ただし、#1 を止めると疑似 CE 自体も止まるため、筐体障害の冗長性評価には独立した CE が必要です。現在の Po99 では VLAN 101 の tagged 端末通信を検証していません。

実配線の確認：CDP の関連行抜粋

実配線の確認.txt

C9300-1#show cdp neighbors GigabitEthernet1/0/33 detail
Device ID: C9300-2
Interface: GigabitEthernet1/0/33,  Port ID (outgoing port): GigabitEthernet1/0/36
Total cdp entries displayed : 1
C9300-1#

C9300-1#show cdp neighbors GigabitEthernet1/0/34 detail
Device ID: C9300-1
Interface: GigabitEthernet1/0/34,  Port ID (outgoing port): GigabitEthernet1/0/36
Total cdp entries displayed : 1
C9300-1#

疑似 CE の設定：#1 のみ

TEST-CE.conf

vrf definition TEST-CE
 !
 address-family ipv4
 exit-address-family
!
interface Port-channel99
 no switchport
 vrf forwarding TEST-CE
 ip address 192.168.33.2 255.255.255.0
!
interface GigabitEthernet1/0/33
 no switchport
 no ip address
 channel-group 99 mode active
 lacp rate fast
!
interface GigabitEthernet1/0/34
 no switchport
 no ip address
 channel-group 99 mode active
 lacp rate fast
!
ip route vrf TEST-CE 0.0.0.0 0.0.0.0 192.168.33.1

3. IP アドレス・VLAN・EVI・VNI

用途	#1	#2
Port-channel48	192.168.255.1/30	192.168.255.2/30
Gi1/0/47・48	IP なし、channel-group 48 mode active	同左
Loopback0 / BGP router ID / VTEP	192.168.255.101/32	192.168.255.102/32
IS-IS NET	49.0001.0000.0000.0101.00	49.0001.0000.0000.0102.00
VLAN 100 SVI	192.168.33.1/24	192.168.33.1/24
VLAN 101 SVI	192.168.34.1/24	192.168.34.1/24

VLAN	EVI	L2VNI	import/export RT	#1 RD	#2 RD
100	100	10100	65100:100	192.168.255.101:100	192.168.255.102:100
101	101	10101	65100:101	192.168.255.101:101	192.168.255.102:101

VLAN・EVI・VNI は別の識別子です。本ラボでは運用上分かりやすい値を選びました。RD は装置ごとに異なり、同じサービスに属する import/export RT は一致しています。実機では RD／RT の自動生成を使用しています。

4. 実機設定を機能単位で読む

以下は今回採取した running-config から、EVPN に必要な範囲を抜粋・整理した設定です。認証・管理機能は省いています。VLAN の作成行は VLAN DB の確認結果に基づき併記しています。既存装置にそのまま全行を再投入する手順ではありません。

4.1 Underlay：IS-IS と core-tracking

両台で ip routing、clns routing、system mtu 9100 を使用しています。Loopback0 を passive とし、Po48 は Level-2 の point-to-point、metric 10 です。IS-IS の NET は装置ごとに変えます。IS-IS 設定ガイド

以下は Po48 と IS-IS の設定です。この構成で疎通・停止試験を実施しています。

MTU 9100 は今回の実機値です。端末側に 9100-byte のパケットを要求する意味ではなく、VXLAN のカプセル化を含めて underlay が運べることを確認します。system MTU の変更は装置全体への影響があるため、既存環境では経路全体の MTU と整合させます。

C9300-1：underlay 設定

C9300-1-underlay.conf

ip routing
clns routing
system mtu 9100
port-channel load-balance src-dst-mixed-ip-port
!
interface Loopback0
 description EVPN_ROUTER_ID_AND_VTEP
 ip address 192.168.255.101 255.255.255.255
!
router isis UNDERLAY
 net 49.0001.0000.0000.0101.00
 is-type level-2-only
 metric-style wide
 log-adjacency-changes
 passive-interface Loopback0
!
interface Port-channel48
 no switchport
 ip address 192.168.255.1 255.255.255.252
 no ip redirects
 ip router isis UNDERLAY
 isis network point-to-point
 isis metric 10 level-2
 evpn multihoming core-tracking
!
interface GigabitEthernet1/0/47
 description EVPN_INTER_ES_PO48_MEMBER
 no switchport
 no ip address
 channel-protocol lacp
 channel-group 48 mode active
 lacp rate fast
!
interface GigabitEthernet1/0/48
 description EVPN_INTER_ES_PO48_MEMBER
 no switchport
 no ip address
 channel-protocol lacp
 channel-group 48 mode active
 lacp rate fast

C9300-2：underlay 設定

C9300-2-underlay.conf

ip routing
clns routing
system mtu 9100
port-channel load-balance src-dst-mixed-ip-port
!
interface Loopback0
 description EVPN_ROUTER_ID_AND_VTEP
 ip address 192.168.255.102 255.255.255.255
!
router isis UNDERLAY
 net 49.0001.0000.0000.0102.00
 is-type level-2-only
 metric-style wide
 log-adjacency-changes
 passive-interface Loopback0
!
interface Port-channel48
 no switchport
 ip address 192.168.255.2 255.255.255.252
 no ip redirects
 ip router isis UNDERLAY
 isis network point-to-point
 isis metric 10 level-2
 evpn multihoming core-tracking
!
interface GigabitEthernet1/0/47
 description EVPN_INTER_ES_PO48_MEMBER
 no switchport
 no ip address
 channel-protocol lacp
 channel-group 48 mode active
 lacp rate fast
!
interface GigabitEthernet1/0/48
 description EVPN_INTER_ES_PO48_MEMBER
 no switchport
 no ip address
 channel-protocol lacp
 channel-group 48 mode active
 lacp rate fast

本構成では、Po48 に BFD を設定していません。non-fabric ガイドの inter-ES L3 EtherChannel 基本例も、IPv4・IGP・Loopback・core-tracking を使用し、当該 Port-channel に BFD を追加していません。同じ章の Layer 3 Routed EVPN Multihoming Networks で使う BFD は、FW 向け SVI／eBGP の例です。inter-ES Port-channel の必須設定とは区別します。実機で BFD なしの片系・両系停止を検証した結果は後述します。

直結した MH ペアでは、物理リンクの障害検出と EtherChannel によるメンバー切替、IGP の経路更新、BGP の fall-over host-route、EVPN core-tracking を組み合わせます。開発者からも、直結リンクのハードウェア支援による障害検出・回復とホスト経路監視を組み合わせる構成では、BFD の追加は多くの場合に役割が重複するとの説明を得ています。この構成で通常の物理断に対する検出・保護を行えるため、inter-ES Po48 の基本構成には BFD を追加していません。ガイドの参照構成も、MH ペア間の iBGP に fall-over host-route を使用しています。non-fabric 参照構成

BFD は、物理リンクが Up のまま起きる転送障害など、追加の検出要件に応じて検討する機能です。core-tracking や経路監視と同じ検査を行うわけではありません。Port-channel 上の 750 ms × 3 という制約と、BFD を使用した場合の参考測定は後半に掲載します。

4.2 EVPN iBGP

相手 Loopback0 を neighbor とし、送信元を Loopback0 に固定します。EVPN address-family で neighbor を activate し、community を交換します。L2 overlay 設定ガイド

両台の EVPN peer に neighbor <対向 Loopback0> fall-over host-route を設定します。対向 Loopback0 の /32 ホスト経路が失われたときに、BGP Hold Timer の満了を待たずにセッションを停止するための設定です。このラボでは GRT に上位 MX 向けのデフォルトルートもありますが、その存在と対向 /32 の存在を区別します。Po48 を Up に保って /32 の広告だけを止める試験と、Po48 全体を停止する試験で動作を確認しています。BGP Fast Session Deactivation

C9300-1：EVPN 用 BGP 設定（上位向け IPv4 AF は後述）

C9300-1-evpn-bgp.conf

router bgp 65100
 bgp router-id interface Loopback0
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 192.168.255.102 remote-as 65100
 neighbor 192.168.255.102 description C9300-2_EVPN
 neighbor 192.168.255.102 update-source Loopback0
 neighbor 192.168.255.102 fall-over host-route
 !
 !
 address-family l2vpn evpn
  neighbor 192.168.255.102 activate
  neighbor 192.168.255.102 send-community both
 exit-address-family

C9300-2：EVPN 用 BGP 設定（上位向け IPv4 AF は後述）

C9300-2-evpn-bgp.conf

router bgp 65100
 bgp router-id interface Loopback0
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 192.168.255.101 remote-as 65100
 neighbor 192.168.255.101 description C9300-1_EVPN
 neighbor 192.168.255.101 update-source Loopback0
 neighbor 192.168.255.101 fall-over host-route
 !
 !
 address-family l2vpn evpn
  neighbor 192.168.255.101 activate
  neighbor 192.168.255.101 send-community both
 exit-address-family

4.3 EVPN 共通設定・VLAN と VNI・NVE

両台に同じ EVI／L2VNI を作り、NVE の source を各自の Loopback0 にします。replication-type ingress と NVE の ingress-replication を使っています。L2 overlay 設定ガイド

multihoming peering adjacent、multihoming aliasing disable、multicast advertise sync-only は non-fabric 設定ガイドと対応させて確認した項目です。
今回の実機には advertise mac disable も入っています。後述の出力では MAC-only advertisement は Disabled ですが、IPv4 を伴う端末の Type 2 は広告されています。

両台共通：EVPN・EVI・VLAN・NVE の設定

common-evpn.conf

l2vpn evpn
 replication-type ingress
 router-id Loopback0
 multihoming peering adjacent
 multihoming aliasing disable
 multicast advertise sync-only
 anycast-gateway mac auto
 advertise mac disable
!
l2vpn evpn instance 100 vlan-based
 encapsulation vxlan
!
l2vpn evpn instance 101 vlan-based
 encapsulation vxlan
!
vlan 100
!
vlan 101
!
vlan configuration 100
 member evpn-instance 100 vni 10100
!
vlan configuration 101
 member evpn-instance 101 vni 10101
!
interface nve1
 description EVPN_INTER_ES_VXLAN
 no ip address
 source-interface Loopback0
 host-reachability protocol bgp
 member vni 10100 ingress-replication
 member vni 10101 ingress-replication

4.4 ES Port-channel と LACP

Po36 の native VLAN を 100、allowed VLAN を 100,101 にします。各スイッチの Gi1/0/36 をローカルの Po36 に1本ずつ入れます。Po36 の evpn ethernet-segment auto lacp df-election wait-time 1 によって LACP 情報に基づく ES を使用します。

物理メンバーと Port-channel の switchport mode、native／allowed VLAN を揃えることも確認点です。

C9300-1：Po36 と物理メンバーの設定

C9300-1-ES.conf

interface Port-channel36
 description EVPN_MH_TO_COMMON_CE
 switchport trunk native vlan 100
 switchport trunk allowed vlan 100,101
 switchport mode trunk
 switchport nonegotiate
 evpn ethernet-segment auto lacp df-election wait-time 1
!
interface GigabitEthernet1/0/36
 description LACP_TO_COMMON_CE_MEMBER_1
 switchport trunk native vlan 100
 switchport trunk allowed vlan 100,101
 switchport mode trunk
 switchport nonegotiate
 channel-protocol lacp
 channel-group 36 mode active
 lacp rate fast

C9300-2：Po36 と物理メンバーの設定

C9300-2-ES.conf

interface Port-channel36
 description EVPN_MH_TO_COMMON_CE
 switchport trunk native vlan 100
 switchport trunk allowed vlan 100,101
 switchport mode trunk
 switchport nonegotiate
 evpn ethernet-segment auto lacp df-election wait-time 1
!
interface GigabitEthernet1/0/36
 description LACP_TO_COMMON_CE_MEMBER_2
 switchport trunk native vlan 100
 switchport trunk allowed vlan 100,101
 switchport mode trunk
 switchport nonegotiate
 channel-protocol lacp
 channel-group 36 mode active
 lacp rate fast

4.5 Anycast Gateway と DHCP relay

両台の SVI に同じ IP アドレスを設定します。今回の Global Anycast Gateway MAC は Auto、SVI の MAC は両台とも 0000.5e00.0101 です。SVI は GRT に属し、EVPN の L3VNI は作成していません。
Anycast SVI に FHRP を重ねる構成は non-fabric 設定ガイドの制約に従って避けます。

DHCP は SVI の helper から外部 Kea 2台へ中継します。ローカル DHCP pool はありません。リレーに必要な DHCP 機能自体を no service dhcp で止める設定にはしません。DHCP サーバー側のスコープ／HA 設計はこの記事の範囲外です。

両台共通：VLAN 100／101 の SVI 設定

common-SVI.conf

interface Vlan100
 description ANYCAST_GATEWAY_VLAN100
 ip address 192.168.33.1 255.255.255.0
 ip helper-address 192.168.64.16
 ip helper-address 192.168.64.17
!
interface Vlan101
 description ANYCAST_GATEWAY_VLAN101
 ip address 192.168.34.1 255.255.255.0
 ip helper-address 192.168.64.16
 ip helper-address 192.168.64.17

5. 設定ガイドの show コマンドで確認する

検証の主軸は non-fabric ガイドの Verifyと L2 overlay ガイドの Verifyingに掲載されたコマンドです。引数の VLAN／EVI／VNI はこのラボに合わせています。IS-IS／BFD の show は各 routing guide、LACP neighbor や実配線確認は補助確認として分けました。

確認する層	通常状態の確認結果
Underlay	Po48(RU)、Gi47(P)・Gi48(P)、IS-IS L2 隣接1本。BFD は未設定
EVPN control plane	iBGP Established、相手から5 prefix を受信
Ethernet Segment	両台で同じ ESI、all-active、Ready、Core Isolation: No
DF	VLAN 100 は #1、VLAN 101 は #2 が forwarding
Access LAG	両台とも Po36(SU)、Gi1/0/36(P)
VXLAN	VNI 10100／10101 が Up、相手 VTEP が UP
Endpoint	VLAN 100 の 192.168.33.2 が MAC/IP 学習済み。VLAN 101 は端末未学習
Gateway	両台の同じ SVI IP に同じ Anycast MAC

5.1 Underlay：隣接だけでなく VTEP の経路を見る

まず Po48(RU) と両メンバーの P を確認します。IS-IS 隣接は Po48 上の1本で、対向 Loopback0 の /32 は Po48 経由です。RIB と CEF の両方を照合します。
隣接が UP でも VTEP の経路が欠けていれば、EVPN セッションと VXLAN の到達性を支えられません。

本ラボでは両台に port-channel load-balance src-dst-mixed-ip-port を設定しています。IP トラフィックでは送信元・宛先 IP と TCP/UDP ポートを用いる方式です。フローごとの振り分けであり、2本のメンバーへの均等分散は今回の検証対象に含めていません。負荷分散の設定は対象機種の CLI とコマンドリファレンスで確認します。C9300-48P／IOS XE 26.2.1 の両実機ではこの設定名を使用し、non-fabric ガイドの例にある vlan-src-dst-mixed-ip-port とは区別します。

装置間 L3 EtherChannel：両メンバーの束ねとハッシュ

装置間 L3 EtherChannel.txt

C9300-1#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 4
Number of aggregators:           4

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
C9300-1#

C9300-1#show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
        src-dst-mixed-ip-port

EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination IP address and TCP/UDP (layer-4) port number
  IPv6: Source XOR Destination IP address and TCP/UDP (layer-4) port number
C9300-1#

C9300-2#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 3
Number of aggregators:           3

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
C9300-2#

C9300-2#show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
        src-dst-mixed-ip-port

EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination IP address and TCP/UDP (layer-4) port number
  IPv6: Source XOR Destination IP address and TCP/UDP (layer-4) port number
C9300-2#

装置間 L3 EtherChannel：詳細（#1）

装置間 L3 EtherChannel.txt

C9300-1#show etherchannel 48 detail
Group state = L3
Ports: 2   Maxports = 16
Port-channels: 1 Max Port-channels = 16
Protocol:   LACP
Minimum Links: 0


		Ports in the group:
		-------------------
Port: Gi1/0/47
------------

Port state    = Up Mstr Assoc In-Bndl
Channel group = 48          Mode = Active          Gcchange = -
Port-channel  = Po48        GC   =   -             Pseudo port-channel = Po48
Port index    = 0           Load = 0x00            Protocol =   LACP

Flags:  S - Device is sending Slow LACPDUs   F - Device is sending fast LACPDUs.
        A - Device is in active mode.        P - Device is in passive mode.

Local information:
                                LACP port    Admin     Oper    Port        Port
Port          Flags   State     Priority     Key       Key     Number      State
Gi1/0/47      FA      bndl      32768        0x30      0x30    0x130       0x3F

 Partner's information:

                     LACP port                      Admin  Oper   Port    Port
Port          Flags  Priority  Dev ID          Age  key    Key    Number  State
Gi1/0/47      FA     32768     0200.0000.0080   0s  0x0    0x30   0x130   0x3F

Age of the port in the current state: 0d:00h:01m:39s

Port: Gi1/0/48
------------

Port state    = Up Mstr Assoc In-Bndl
Channel group = 48          Mode = Active          Gcchange = -
Port-channel  = Po48        GC   =   -             Pseudo port-channel = Po48
Port index    = 0           Load = 0x00            Protocol =   LACP

Flags:  S - Device is sending Slow LACPDUs   F - Device is sending fast LACPDUs.
        A - Device is in active mode.        P - Device is in passive mode.

Local information:
                                LACP port    Admin     Oper    Port        Port
Port          Flags   State     Priority     Key       Key     Number      State
Gi1/0/48      FA      bndl      32768        0x30      0x30    0x131       0x3F

 Partner's information:

                     LACP port                      Admin  Oper   Port    Port
Port          Flags  Priority  Dev ID          Age  key    Key    Number  State
Gi1/0/48      FA     32768     0200.0000.0080   0s  0x0    0x30   0x131   0x3F

Age of the port in the current state: 0d:00h:01m:39s

		Port-channels in the group:
		---------------------------

Port-channel: Po48    (Primary Aggregator)

------------

Age of the Port-channel   = 0d:02h:05m:35s
Logical slot/port   = 35/48          Number of ports = 2
HotStandBy port = null
Passive port list   = Gi1/0/47 Gi1/0/48
Port state          = Port-channel L3-Ag Ag-Inuse
Protocol            =   LACP
Port security       = Disabled
Fast-switchover     = disabled
Fast-switchover Dampening = disabled

Ports in the Port-channel:

Index   Load   Port        EC state        No of bits
------+------+------+------------------+-----------
  0     00     Gi1/0/47       Active             0
  0     00     Gi1/0/48       Active             0

Time since last port bundled:    0d:00h:01m:39s     Gi1/0/47
Time since last port Un-bundled: 0d:00h:01m:52s     Gi1/0/48
C9300-1#

IS-IS：隣接とプロトコル設定

IS-IS.txt

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2     L2   Po48          192.168.255.2   UP    29       58
C9300-1#

C9300-1#show isis protocol
Tag UNDERLAY:
IS-IS Router: UNDERLAY (0x20000)
  System Id: 0000.0000.0101.00  IS-Type: level-2  lsp-mtu: 1492
  Manual area address(es):
	49.0001
  Routing for area address(es):
	49.0001
  Interfaces supported by IS-IS:
	Port-channel48 - IP
  Passive interface:
	Loopback0
  Generate wide metrics:   level-1-2
  Accept wide metrics:     level-1-2
C9300-1#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1     L2   Po48          192.168.255.1   UP    21       5A
C9300-2#

C9300-2#show isis protocol
Tag UNDERLAY:
IS-IS Router: UNDERLAY (0x20000)
  System Id: 0000.0000.0102.00  IS-Type: level-2  lsp-mtu: 1492
  Manual area address(es):
	49.0001
  Routing for area address(es):
	49.0001
  Interfaces supported by IS-IS:
	Port-channel48 - IP
  Passive interface:
	Loopback0
  Generate wide metrics:   level-1-2
  Accept wide metrics:     level-1-2
C9300-2#

C9300-1：相手 VTEP の RIB／CEF

C9300-1.txt

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:01:28 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:01:28 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-1#show ip cef 192.168.255.102 detail
192.168.255.102/32, epoch 3
  1 RR source [no flags]
  nexthop 192.168.255.2 Port-channel48
C9300-1#

C9300-2：相手 VTEP の RIB／CEF

C9300-2.txt

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:01:30 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:01:30 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

C9300-2#show ip cef 192.168.255.101 detail
192.168.255.101/32, epoch 3
  1 RR source [no flags]
  nexthop 192.168.255.1 Port-channel48
C9300-2#

本構成に BFD セッションがないことも確認します。Po48 の running-config に BFD の interval／IS-IS 連携設定がなく、以下の出力も空です。BFD を使わなくても、IS-IS と EVPN が成立していることを前後の出力と照合できます。

BFD を使用していないことの確認

BFD を使用していないことの確認.txt

C9300-1#show bfd neighbors details

C9300-1#

C9300-2#show bfd neighbors details

C9300-2#

5.2 Core tracking：追跡対象の範囲を意識する

今回追跡しているのは Port-channel48 です。ガイドの Core Isolation and Interface Trackingは、インターフェイスと iBGP の状態を組み合わせた監視、および孤立時のローカル ES ポート保護と自動復旧を説明しています。IF の Up 表示を転送経路の疎通試験と同じ意味にはしません。

機能	主な役割	今回の配置
LACP	メンバーの束ね・参加状態の制御	Gi47／Gi48、fast／active
IS-IS	対向 Loopback の経路を生成・更新	Po48、Level-2 point-to-point
BGP fall-over host-route	対向 /32 の喪失を受けて EVPN BGP セッションを停止	両台の Loopback EVPN peer
EVPN core-tracking	設定した IF と iBGP の状態に基づく ES の孤立保護・復旧	Po48 を追跡
BFD	隣接装置間の転送経路を監視し、登録したルーティングプロトコルへ障害を通知	基本構成では未使用。追加検証は実施

BFD の役割は BFD 設定ガイドで確認できます。リンクが Up のまま転送が失われる障害など、追加の検出要件があれば採用を検討します。

上位 MX 向け Gi1/0/1 は今回の core-tracking 対象ではありません。追跡対象 IF の選択と、対向 Loopback に到達できる代替 IP 経路の設計をあわせて検討します。core-tracking が代替経路を自動生成するわけではありません。

Core tracking：L3 Po48 の状態

Core tracking.txt

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

5.3 EVPN：summary と BGP テーブルを対応させる

通常状態の採取例では、両台とも相手から 5 prefix を受信しています。summary の State/PfxRcd が数値であればセッションは Established です。0 も数値なので、経路件数が0という意味であり、Idle と同じ意味ではありません。経路がない理由は EVI／ES／端末の状態まで下りて確認します。

EVPN：全体 summary と BGP neighbor

EVPN.txt

C9300-1#show l2vpn evpn summary
L2VPN EVPN
  EVPN Instances (excluding point-to-point): 2
    VLAN Based:   2
  BGP: ASN 65100, address-family l2vpn evpn configured
  Router ID: 192.168.255.101
  Global Replication Type: Ingress
  Connectivity to Core: UP
    BGP core status: UP
    Core link status: UP
    NVE status: UP
    Duplicate: 0
    Duplicate: 0
  Multi-home aliasing: Disabled
  Multi-home send proxy MAC/IP: Enabled
  Multi-home device ID: 0000.5e00.0101
  Multi-home peering adjacent: Enabled
  Multihoming Ethernet Segment bringup: Complete
  Auto route-target: evi-id based
  Global Anycast Gateway MAC: Auto
  MAC Only Advertisement: Disabled
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 216, main routing table version 216
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100       9      10      216    0    0 00:01:25        5
C9300-1#

C9300-2#show l2vpn evpn summary
L2VPN EVPN
  EVPN Instances (excluding point-to-point): 2
    VLAN Based:   2
  BGP: ASN 65100, address-family l2vpn evpn configured
  Router ID: 192.168.255.102
  Global Replication Type: Ingress
  Connectivity to Core: UP
    BGP core status: UP
    Core link status: UP
    NVE status: UP
    Duplicate: 0
    Duplicate: 0
  Multi-home aliasing: Disabled
  Multi-home send proxy MAC/IP: Enabled
  Multi-home device ID: 0000.5e00.0101
  Multi-home peering adjacent: Enabled
  Multihoming Ethernet Segment bringup: Complete
  Auto route-target: evi-id based
  Global Anycast Gateway MAC: Auto
  MAC Only Advertisement: Disabled
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 231, main routing table version 231
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100      10       9      231    0    0 00:01:27        5
C9300-2#

EVPN：通常状態の BGP テーブル（#1）

EVPN.txt

C9300-1#show bgp l2vpn evpn
BGP table version is 216, local router ID is 192.168.255.101
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
              t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 192.168.255.101:9
 *>   [1][192.168.255.101:9][01020000000099006300][4294967295]/23
                      0.0.0.0                            32768 ?
Route Distinguisher: 192.168.255.102:6
 *>i  [1][192.168.255.102:6][01020000000099006300][4294967295]/23
                      192.168.255.102          0    100      0 ?
Route Distinguisher: 192.168.255.101:100
 *mi  [2][192.168.255.101:100][0][48][020000000002][32][192.168.33.2]/24
                      192.168.255.102          0    100      0 ?
 *>                    0.0.0.0                            32768 ?
Route Distinguisher: 192.168.255.102:100
 *>i  [2][192.168.255.102:100][0][48][020000000002][32][192.168.33.2]/24
                      192.168.255.102          0    100      0 ?
Route Distinguisher: 192.168.255.101:100
 *>   [3][192.168.255.101:100][0][32][192.168.255.101]/17
                      0.0.0.0                            32768 ?
 *>i  [3][192.168.255.101:100][0][32][192.168.255.102]/17
                      192.168.255.102          0    100      0 ?
Route Distinguisher: 192.168.255.101:101
 *>   [3][192.168.255.101:101][0][32][192.168.255.101]/17
                      0.0.0.0                            32768 ?
 *>i  [3][192.168.255.101:101][0][32][192.168.255.102]/17
                      192.168.255.102          0    100      0 ?
Route Distinguisher: 192.168.255.102:100
 *>i  [3][192.168.255.102:100][0][32][192.168.255.102]/17
                      192.168.255.102          0    100      0 ?
Route Distinguisher: 192.168.255.102:101
 *>i  [3][192.168.255.102:101][0][32][192.168.255.102]/17
                      192.168.255.102          0    100      0 ?
Route Distinguisher: 192.168.255.101:25344
 *>   [4][192.168.255.101:25344][01020000000099006300][32][192.168.255.101]/23
                      0.0.0.0                            32768 ?
Route Distinguisher: 192.168.255.102:25344
 *>i  [4][192.168.255.102:25344][01020000000099006300][32][192.168.255.102]/23
                      192.168.255.102          0    100      0 ?
C9300-1#

BGP 経路監視：fall-over host-route と neighbor 詳細

bgp-fallover.txt

C9300-1#show bgp l2vpn evpn neighbors 192.168.255.102
BGP neighbor is 192.168.255.102,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Established, up for 00:01:24
  Last read 00:00:30, last write 00:00:30, hold time is 180, keepalive interval is 60 seconds
  Route to peer address reachability Up: 28; Down: 0
  Last reset 00:01:48, due to Route to peer lost of session 1
C9300-1#

C9300-2#show bgp l2vpn evpn neighbors 192.168.255.101
BGP neighbor is 192.168.255.101,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Established, up for 00:01:24
  Last read 00:00:30, last write 00:00:30, hold time is 180, keepalive interval is 60 seconds
  Route to peer address reachability Up: 27; Down: 0
  Last reset 00:01:47, due to Route to peer lost of session 1
C9300-2#

5.4 Route Type ごとに何を見ているか整理する

Type 1〜4 の基本は RFC 7432、Type 5 は RFC 9136、VXLAN への適用は RFC 8365を参照できます。今回は次のように実機出力と対応させました。

Type	内容	今回の観測
1	Ethernet Auto-Discovery	両 PE が広告する per-ES ルート。Ethernet Tag は 4294967295
2	MAC/IP Advertisement	VLAN 100 の 192.168.33.2 と MAC、ESI、Label1 10100
3	IMET	VNI ごとの Ingress Replication 参加情報
4	Ethernet Segment	同じ ES を収容する PE の発見・DF 選出に使う情報
5	IP Prefix	今回の EVPN テーブルには存在しない

Type 2 の表示末尾の /24 は、通常の IPv4 unicast RIB にある 192.168.33.0/24 の広告と同じ読み方にはしません。ここでは NLRI の [32][192.168.33.2] と、詳細出力の MAC／ESI／VNI を確認します。

Type 5 がなくても、この non-fabric 構成では GRT の SVI と通常の IPv4 ルーティングを使用できます。上位への /24 広告は後述の IPv4 unicast AF で確認します。

Type 1／4：ES の到達性と ES 発見（#1）

Type 1／4.txt

C9300-1#show bgp l2vpn evpn route-type 1
BGP routing table entry for [1][192.168.255.101:9][01020000000099006300][4294967295]/23, version 210
Paths: (1 available, best #1, table EVPN-BGP-Table)
    0.0.0.0 (via default) from 0.0.0.0 (192.168.255.101)
      Origin incomplete, localpref 100, weight 32768, valid, sourced, local, best
      Extended Community: RT:65100:100 RT:65100:101 ENCAP:8
        EVPN LABEL:0x0:Label-0
BGP routing table entry for [1][192.168.255.102:6][01020000000099006300][4294967295]/23, version 204
Paths: (1 available, best #1, table EVPN-BGP-Table)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:65100:100 RT:65100:101 ENCAP:8
        EVPN LABEL:0x0:Label-0
C9300-1#

C9300-1#show bgp l2vpn evpn route-type 4
BGP routing table entry for [4][192.168.255.101:25344][01020000000099006300][32][192.168.255.101]/23, version 211
Paths: (1 available, best #1, table EVPN-BGP-Table)
    0.0.0.0 (via default) from 0.0.0.0 (192.168.255.101)
      Origin incomplete, localpref 100, weight 32768, valid, sourced, local, best
      Extended Community: ENCAP:8 EVPN ES-IMPORT:0x0200:0x0000:0x0099
BGP routing table entry for [4][192.168.255.102:25344][01020000000099006300][32][192.168.255.102]/23, version 205
Paths: (1 available, best #1, table EVPN-BGP-Table)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      Extended Community: ENCAP:8 EVPN ES-IMPORT:0x0200:0x0000:0x0099
C9300-1#

Type 2：両台の MAC/IP 経路詳細

Type 2.txt

C9300-1#show bgp l2vpn evpn route-type 2
BGP routing table entry for [2][192.168.255.101:100][0][48][020000000002][32][192.168.33.2]/24, version 216
Paths: (2 available, best #2, table evi_100)
  Local, imported path from [2][192.168.255.102:100][0][48][020000000002][32][192.168.33.2]/24 (global)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, multipath(oldest)
      EVPN ESI: 01020000000099006300, Label1 10100
      Extended Community: RT:65100:100 ENCAP:8 EVPN ARP/ND:1024
    0.0.0.0 (via default) from 0.0.0.0 (192.168.255.101)
      Origin incomplete, localpref 100, weight 32768, valid, sourced, local, multipath, best
      EVPN ESI: 01020000000099006300, Label1 10100
      Extended Community: RT:65100:100 ENCAP:8
BGP routing table entry for [2][192.168.255.102:100][0][48][020000000002][32][192.168.33.2]/24, version 215
Paths: (1 available, best #1, table EVPN-BGP-Table)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      EVPN ESI: 01020000000099006300, Label1 10100
      Extended Community: RT:65100:100 ENCAP:8 EVPN ARP/ND:1024
C9300-1#

C9300-2#show bgp l2vpn evpn route-type 2
BGP routing table entry for [2][192.168.255.101:100][0][48][020000000002][32][192.168.33.2]/24, version 229
Paths: (1 available, best #1, table EVPN-BGP-Table)
    192.168.255.101 (metric 10) (via default) from 192.168.255.101 (192.168.255.101)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      EVPN ESI: 01020000000099006300, Label1 10100
      Extended Community: RT:65100:100 ENCAP:8
BGP routing table entry for [2][192.168.255.102:100][0][48][020000000002][32][192.168.33.2]/24, version 231
Paths: (2 available, best #1, table evi_100)
    0.0.0.0 (via default) from 0.0.0.0 (192.168.255.102)
      Origin incomplete, localpref 100, weight 32768, valid, sourced, local, multipath, best
      EVPN ESI: 01020000000099006300, Label1 10100
      Extended Community: RT:65100:100 ENCAP:8 EVPN ARP/ND:1024
  Local, imported path from [2][192.168.255.101:100][0][48][020000000002][32][192.168.33.2]/24 (global)
    192.168.255.101 (metric 10) (via default) from 192.168.255.101 (192.168.255.101)
      Origin incomplete, metric 0, localpref 100, valid, internal, multipath(oldest)
      EVPN ESI: 01020000000099006300, Label1 10100
      Extended Community: RT:65100:100 ENCAP:8
C9300-2#

Type 3／5：IMET と IP Prefix の有無（#1）

Type 3／5.txt

C9300-1#show bgp l2vpn evpn route-type 3
BGP routing table entry for [3][192.168.255.101:100][0][32][192.168.255.101]/17, version 212
Paths: (1 available, best #1, table evi_100)
    0.0.0.0 (via default) from 0.0.0.0 (192.168.255.101)
      Origin incomplete, localpref 100, weight 32768, valid, sourced, local, best
      Extended Community: RT:65100:100 ENCAP:8 EVPN Mcast Flags:1
      PMSI Attribute: Flags:0x0, Tunnel type:IR, length 4, vni:10100, tunnel identifier: 0000 0000
BGP routing table entry for [3][192.168.255.101:100][0][32][192.168.255.102]/17, version 208
Paths: (1 available, best #1, table evi_100)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:65100:100 ENCAP:8 EVPN Mcast Flags:1
      PMSI Attribute: Flags:0x0, Tunnel type:IR, length 4, vni:10100, tunnel identifier: < Tunnel Endpoint: 192.168.255.102 >
BGP routing table entry for [3][192.168.255.101:101][0][32][192.168.255.101]/17, version 213
Paths: (1 available, best #1, table evi_101)
    0.0.0.0 (via default) from 0.0.0.0 (192.168.255.101)
      Origin incomplete, localpref 100, weight 32768, valid, sourced, local, best
      Extended Community: RT:65100:101 ENCAP:8 EVPN Mcast Flags:1
      PMSI Attribute: Flags:0x0, Tunnel type:IR, length 4, vni:10101, tunnel identifier: 0000 0000
BGP routing table entry for [3][192.168.255.101:101][0][32][192.168.255.102]/17, version 209
Paths: (1 available, best #1, table evi_101)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:65100:101 ENCAP:8 EVPN Mcast Flags:1
      PMSI Attribute: Flags:0x0, Tunnel type:IR, length 4, vni:10101, tunnel identifier: < Tunnel Endpoint: 192.168.255.102 >
BGP routing table entry for [3][192.168.255.102:100][0][32][192.168.255.102]/17, version 206
Paths: (1 available, best #1, table EVPN-BGP-Table)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:65100:100 ENCAP:8 EVPN Mcast Flags:1
      PMSI Attribute: Flags:0x0, Tunnel type:IR, length 4, vni:10100, tunnel identifier: < Tunnel Endpoint: 192.168.255.102 >
BGP routing table entry for [3][192.168.255.102:101][0][32][192.168.255.102]/17, version 207
Paths: (1 available, best #1, table EVPN-BGP-Table)
    192.168.255.102 (metric 10) (via default) from 192.168.255.102 (192.168.255.102)
      Origin incomplete, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:65100:101 ENCAP:8 EVPN Mcast Flags:1
      PMSI Attribute: Flags:0x0, Tunnel type:IR, length 4, vni:10101, tunnel identifier: < Tunnel Endpoint: 192.168.255.102 >
C9300-1#

C9300-1#show bgp l2vpn evpn route-type 5
% Network not in table
C9300-1#

5.5 ES と DF：all-active と BUM 制御を分けて読む

両台の ESI は同一で、Redundancy mode は all-active、State は Ready です。Forwarder List に .101 と .102 が入っています。

EVI / VLAN	#1	#2
100	forwarding（DF）	PE-to-CE BUM blocked（non-DF）
101	PE-to-CE BUM blocked（non-DF）	forwarding（DF）

この DF state は PE → CE 方向の BUM 転送を制御する表示です。non-DF 側の物理リンク全体が使えないことを意味しません。両台の Po36 が使用中かどうかは LACP とあわせて確認します。All-Active Mode Overview / RFC 7432 の DF 選出

ES：同一 ESI・all-active・Ready と Forwarder List

ES.txt

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:9
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment forwarder
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:6
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment forwarder
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

EVI 100：両台の詳細と DF state

EVI 100.txt

C9300-1#show l2vpn evpn evi 100 detail
EVPN instance:              100 (VLAN Based)
  RD:                       192.168.255.101:100 (auto)
  Import-RTs:               65100:100
  Export-RTs:               65100:100
  State:                    Established
  Replication Type:         Ingress (global)
  Encapsulation:            vxlan
  Multihoming Aliasing:     Disabled (global)
  Multihoming Proxy MAC/IP: Enabled (global)
  Adv. Def. Gateway:        Disabled (global)
  Adv. MAC Only:            Disabled (global)
  Vlan:                     100
    State:                  Established
    Access If:              Vlan100
    NVE If:                 nve1
    Core Vlan:              0
    L2 VNI:                 10100
    L3 VNI:                 0
    VTEP IP:                192.168.255.101
    VRF:
    IPv4 IRB:               Enabled (Asymmetric)
    Pseudoports:
      Port-channel36 service instance 100 (DF state: forwarding)
        Routes: 2 MAC, 1 MAC/IP
        ESI: 0102.0000.0000.9900.6300
    Peers:
      192.168.255.102
        Routes: 1 MAC, 1 MAC/IP, 1 IMET, 0 EAD, 0 SMET, 0 JOIN-SYNC, 0 LEAVE-SYNC
C9300-1#

C9300-2#show l2vpn evpn evi 100 detail
EVPN instance:              100 (VLAN Based)
  RD:                       192.168.255.102:100 (auto)
  Import-RTs:               65100:100
  Export-RTs:               65100:100
  State:                    Established
  Replication Type:         Ingress (global)
  Encapsulation:            vxlan
  Multihoming Aliasing:     Disabled (global)
  Multihoming Proxy MAC/IP: Enabled (global)
  Adv. Def. Gateway:        Disabled (global)
  Adv. MAC Only:            Disabled (global)
  Vlan:                     100
    State:                  Established
    Access If:              Vlan100
    NVE If:                 nve1
    Core Vlan:              0
    L2 VNI:                 10100
    L3 VNI:                 0
    VTEP IP:                192.168.255.102
    VRF:
    IPv4 IRB:               Enabled (Asymmetric)
    Pseudoports:
      Port-channel36 service instance 100 (DF state: PE-to-CE BUM blocked)
        Routes: 1 MAC, 1 MAC/IP
        ESI: 0102.0000.0000.9900.6300
    Peers:
      192.168.255.101
        Routes: 1 MAC, 1 MAC/IP, 1 IMET, 0 EAD, 0 SMET, 0 JOIN-SYNC, 0 LEAVE-SYNC
C9300-2#

EVI 101：両台の詳細と DF state

EVI 101.txt

C9300-1#show l2vpn evpn evi 101 detail
EVPN instance:              101 (VLAN Based)
  RD:                       192.168.255.101:101 (auto)
  Import-RTs:               65100:101
  Export-RTs:               65100:101
  State:                    Established
  Replication Type:         Ingress (global)
  Encapsulation:            vxlan
  Multihoming Aliasing:     Disabled (global)
  Multihoming Proxy MAC/IP: Enabled (global)
  Adv. Def. Gateway:        Disabled (global)
  Adv. MAC Only:            Disabled (global)
  Vlan:                     101
    State:                  Established
    Access If:              Vlan101
    NVE If:                 nve1
    Core Vlan:              0
    L2 VNI:                 10101
    L3 VNI:                 0
    VTEP IP:                192.168.255.101
    VRF:
    IPv4 IRB:               Enabled (Asymmetric)
    Pseudoports:
      Port-channel36 service instance 101 (DF state: PE-to-CE BUM blocked)
        Routes: 0 MAC, 0 MAC/IP
        ESI: 0102.0000.0000.9900.6300
    Peers:
      192.168.255.102
        Routes: 0 MAC, 0 MAC/IP, 1 IMET, 0 EAD, 0 SMET, 0 JOIN-SYNC, 0 LEAVE-SYNC
C9300-1#

C9300-2#show l2vpn evpn evi 101 detail
EVPN instance:              101 (VLAN Based)
  RD:                       192.168.255.102:101 (auto)
  Import-RTs:               65100:101
  Export-RTs:               65100:101
  State:                    Established
  Replication Type:         Ingress (global)
  Encapsulation:            vxlan
  Multihoming Aliasing:     Disabled (global)
  Multihoming Proxy MAC/IP: Enabled (global)
  Adv. Def. Gateway:        Disabled (global)
  Adv. MAC Only:            Disabled (global)
  Vlan:                     101
    State:                  Established
    Access If:              Vlan101
    NVE If:                 nve1
    Core Vlan:              0
    L2 VNI:                 10101
    L3 VNI:                 0
    VTEP IP:                192.168.255.102
    VRF:
    IPv4 IRB:               Enabled (Asymmetric)
    Pseudoports:
      Port-channel36 service instance 101 (DF state: forwarding)
        Routes: 0 MAC, 0 MAC/IP
        ESI: 0102.0000.0000.9900.6300
    Peers:
      192.168.255.101
        Routes: 0 MAC, 0 MAC/IP, 1 IMET, 0 EAD, 0 SMET, 0 JOIN-SYNC, 0 LEAVE-SYNC
C9300-2#

Multihoming Aliasing: Disabled でも、今回の ES は all-active として動作しています。実機では Multi-home send proxy MAC/IP: Enabled と表示され、MAC/IP のデータベースにも proxy next hop が見えます。
per-EVI EAD の広告を無効にする設定と、per-ES EAD 自体の有無は区別します。Type 1 が全くなくなるという意味ではありません。non-fabric ガイド

5.6 LACP：`P` は bundled

両台の Po36 は SU、Gi36 は P でした。

EtherChannel summary の S は Layer 2、U は in use。
同じ出力の P は bundled in port-channel。
LACP neighbor の Flags に出る A／P は Active／Passive。別の出力にある記号です。

したがって、Gi36(P) を見て「LACP が passive になった」とは判定しません。今回の物理インターフェイス設定は channel-group 36 mode active、採取時の稼働メンバーは local／neighbor とも FA です。F は Fast LACPDUs、A は Active で、EtherChannel summary の P とは別のフラグです。

lacp rate fast を物理メンバーに設定しています。Cisco の仕様では fast は1秒、タイムアウトは約3秒です。両方向を揃えるため対向側にも設定します。物理リンクダウン、LACP 無応答、BFD による L3 到達性監視は、それぞれ検出対象が異なります。LACP コマンドリファレンス

LACP：稼働 LAG の summary と情報（関連行抜粋）

LACP.txt

C9300-1#show etherchannel summary
Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
36     Po36(SU)        LACP        Gi1/0/36(P)
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
99     Po99(RU)        LACP        Gi1/0/33(P)     Gi1/0/34(P)
C9300-1#

C9300-1#show lacp internal
Flags:  S - Device is requesting Slow LACPDUs
        F - Device is requesting Fast LACPDUs
        A - Device is in Active mode       P - Device is in Passive mode

Channel group 36
                                LACP port    Admin     Oper    Port        Port
Port          Flags   State     Priority     Key       Key     Number      State
Gi1/0/36      FA      bndl      32768        0x24      0x24    0x125       0x3F

Channel group 48
                                LACP port    Admin     Oper    Port        Port
Port          Flags   State     Priority     Key       Key     Number      State
Gi1/0/47      FA      bndl      32768        0x30      0x30    0x130       0x3F
Gi1/0/48      FA      bndl      32768        0x30      0x30    0x131       0x3F

Channel group 99
                                LACP port    Admin     Oper    Port        Port
Port          Flags   State     Priority     Key       Key     Number      State
Gi1/0/33      FA      bndl      32768        0x63      0x63    0x122       0x3F
Gi1/0/34      FA      bndl      32768        0x63      0x63    0x123       0x3F
C9300-1#

C9300-1#show lacp neighbor
Flags:  S - Device is requesting Slow LACPDUs
        F - Device is requesting Fast LACPDUs
        A - Device is in Active mode       P - Device is in Passive mode

Channel group 36 neighbors

                     LACP port                      Admin  Oper   Port    Port
Port          Flags  Priority  Dev ID          Age  key    Key    Number  State
Gi1/0/36      FA     32768     0200.0000.0099   0s  0x0    0x63   0x123   0x3F

Channel group 48 neighbors

                     LACP port                      Admin  Oper   Port    Port
Port          Flags  Priority  Dev ID          Age  key    Key    Number  State
Gi1/0/47      FA     32768     0200.0000.0080   0s  0x0    0x30   0x130   0x3F
Gi1/0/48      FA     32768     0200.0000.0080   0s  0x0    0x30   0x131   0x3F

Channel group 99 neighbors

                     LACP port                      Admin  Oper   Port    Port
Port          Flags  Priority  Dev ID          Age  key    Key    Number  State
Gi1/0/33      FA     32768     0000.5e00.0101   0s  0x0    0x24   0x125   0x3F
Gi1/0/34      FA     32768     0000.5e00.0101   0s  0x0    0x24   0x125   0x3F
C9300-1#

C9300-2#show etherchannel summary
Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
36     Po36(SU)        LACP        Gi1/0/36(P)
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
C9300-2#

C9300-2#show lacp internal
Flags:  S - Device is requesting Slow LACPDUs
        F - Device is requesting Fast LACPDUs
        A - Device is in Active mode       P - Device is in Passive mode

Channel group 36
                                LACP port    Admin     Oper    Port        Port
Port          Flags   State     Priority     Key       Key     Number      State
Gi1/0/36      FA      bndl      32768        0x24      0x24    0x125       0x3F

Channel group 48
                                LACP port    Admin     Oper    Port        Port
Port          Flags   State     Priority     Key       Key     Number      State
Gi1/0/47      FA      bndl      32768        0x30      0x30    0x130       0x3F
Gi1/0/48      FA      bndl      32768        0x30      0x30    0x131       0x3F
C9300-2#

C9300-2#show lacp neighbor
Flags:  S - Device is requesting Slow LACPDUs
        F - Device is requesting Fast LACPDUs
        A - Device is in Active mode       P - Device is in Passive mode

Channel group 36 neighbors

                     LACP port                      Admin  Oper   Port    Port
Port          Flags  Priority  Dev ID          Age  key    Key    Number  State
Gi1/0/36      FA     32768     0200.0000.0099   0s  0x0    0x63   0x122   0x3F

Channel group 48 neighbors

                     LACP port                      Admin  Oper   Port    Port
Port          Flags  Priority  Dev ID          Age  key    Key    Number  State
Gi1/0/47      FA     32768     0200.0000.0099   0s  0x0    0x30   0x130   0x3F
Gi1/0/48      FA     32768     0200.0000.0099   0s  0x0    0x30   0x131   0x3F
C9300-2#

Trunk／VLAN：native 100 と allowed 100,101

Trunk／VLAN.txt

C9300-1#show interfaces trunk
Port           Mode             Encapsulation  Status        Native vlan
Po36           on               802.1q         trunking      100

Port           Vlans allowed on trunk
Po36           100-101

Port           Vlans allowed and active in management domain
Po36           100-101

Port           Vlans in spanning tree forwarding state and not pruned
Po36           100-101
C9300-1#

C9300-1#show vlan id 100
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
100  EVPN_NATIVE_100                  active    Gi1/0/13, Gi1/0/14, Gi1/0/15, Gi1/0/16, Gi1/0/17, Gi1/0/18, Gi1/0/19, Gi1/0/20, Gi1/0/21, Gi1/0/22, Gi1/0/23, Gi1/0/24, Po36
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
100  enet  100100     1500  -      -      -        -    -        0      0
----------------
------- --------- ----------------- ------------------------------------------
C9300-1#

C9300-1#show vlan id 101
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
101  EVPN_TAGGED_101                  active    Po36
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
101  enet  100101     1500  -      -      -        -    -        0      0
----------------
------- --------- ----------------- ------------------------------------------
C9300-1#

C9300-2#show interfaces trunk
Port           Mode             Encapsulation  Status        Native vlan
Po36           on               802.1q         trunking      100

Port           Vlans allowed on trunk
Po36           100-101

Port           Vlans allowed and active in management domain
Po36           100-101

Port           Vlans in spanning tree forwarding state and not pruned
Po36           100-101
C9300-2#

C9300-2#show vlan id 100
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
100  EVPN_NATIVE_100                  active    Gi1/0/13, Gi1/0/14, Gi1/0/15, Gi1/0/16, Gi1/0/17, Gi1/0/18, Gi1/0/19, Gi1/0/20, Gi1/0/21, Gi1/0/22, Gi1/0/23, Gi1/0/24, Po36
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
100  enet  100100     1500  -      -      -        -    -        0      0
----------------
------- --------- ----------------- ------------------------------------------
C9300-2#

C9300-2#show vlan id 101
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
101  EVPN_TAGGED_101                  active    Po36
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
101  enet  100101     1500  -      -      -        -    -        0      0
----------------
------- --------- ----------------- ------------------------------------------
C9300-2#

VLAN 100 は untagged、VLAN 101 は tagged という接続条件です。装置全体で native VLAN をタグ付けする追加設定を使う場合は、対向を含めた条件を確認します。

5.7 NVE／VNI：VNI ごとの peer と転送情報

VNI 10100／10101 は L2CP モードで Up、相手 VTEP は各 VNI で UP でした。L2CP という表示は BGP を使う制御方式の区別であり、データ転送できないという意味ではありません。
Ingress Replication の IMET も、BGP テーブルと L2route の両方から確認します。L2 overlay ガイド

NVE：VNI と peer の状態

NVE.txt

C9300-1#show nve vni
Interface  VNI        Multicast-group  VNI state  Mode  VLAN  cfg vrf
nve1       10101      N/A              Up         L2CP  101   CLI N/A
nve1       10100      N/A              Up         L2CP  100   CLI N/A
C9300-1#

C9300-1#show nve peers
'M' - MAC entry download flag  'A' - Adjacency download flag
'4' - IPv4 flag  '6' - IPv6 flag

Interface  VNI      Type Peer-IP          RMAC/Num_RTs   eVNI     state flags UP time
nve1       10100    L2CP 192.168.255.102  3              10100      UP   N/A  00:00:39
nve1       10101    L2CP 192.168.255.102  1              10101      UP   N/A  00:00:39
C9300-1#

C9300-2#show nve vni
Interface  VNI        Multicast-group  VNI state  Mode  VLAN  cfg vrf
nve1       10101      N/A              Up         L2CP  101   CLI N/A
nve1       10100      N/A              Up         L2CP  100   CLI N/A
C9300-2#

C9300-2#show nve peers
'M' - MAC entry download flag  'A' - Adjacency download flag
'4' - IPv4 flag  '6' - IPv6 flag

Interface  VNI      Type Peer-IP          RMAC/Num_RTs   eVNI     state flags UP time
nve1       10100    L2CP 192.168.255.101  3              10100      UP   N/A  00:00:41
nve1       10101    L2CP 192.168.255.101  1              10101      UP   N/A  00:00:41
C9300-2#

IMET：VNI ごとの L2route 詳細（#1）

IMET.txt

C9300-1#show l2route evpn imet detail
EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            BGP
Router IP Addr:           192.168.255.102
Route Ethernet Tag:       0
Tunnel Flags:             0
Tunnel Type:              Ingress Replication
Tunnel Labels:            10100
Tunnel ID:                192.168.255.102
Multicast Proxy:          IGMP
Next Hop(s):              V:0 192.168.255.102

EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            L2VPN
Router IP Addr:           192.168.255.101
Route Ethernet Tag:       0
Tunnel Flags:             0
Tunnel Type:              Ingress Replication
Tunnel Labels:            10100
Tunnel ID:                192.168.255.101
Multicast Proxy:          IGMP
Next Hop(s):              N/A

EVPN Instance:            101
Ethernet Tag:             0
Producer Name:            BGP
Router IP Addr:           192.168.255.102
Route Ethernet Tag:       0
Tunnel Flags:             0
Tunnel Type:              Ingress Replication
Tunnel Labels:            10101
Tunnel ID:                192.168.255.102
Multicast Proxy:          IGMP
Next Hop(s):              V:0 192.168.255.102

EVPN Instance:            101
Ethernet Tag:             0
Producer Name:            L2VPN
Router IP Addr:           192.168.255.101
Route Ethernet Tag:       0
Tunnel Flags:             0
Tunnel Type:              Ingress Replication
Tunnel Labels:            10101
Tunnel ID:                192.168.255.101
Multicast Proxy:          IGMP
Next Hop(s):              N/A
C9300-1#

詳細表示の IRB down は、どの項目が down なのか読む

今回の VNI 詳細には、VNI 自体は Up の一方、L2CP VNI IRB state: IPv4 down、BDI’s VRF un-configured、Local routing: Disabled が出ています。
同時に EVI 詳細は IPv4 IRB Enabled (Asymmetric)、L3 VNI 0、SVI は GRT に所属しています。これらの表示を一括して「EVPN 全体 down」と読み替えず、L2VNI／EVPN IP-VRF に関する詳細項目と、GRT SVI の状態・実際の疎通を照合します。今回、GRT SVI を経由する TEST-CE の疎通は後述のとおり成功しました。

NVE 詳細：VNI Up と IRB 詳細項目の併記（#1）

NVE 詳細.txt

C9300-1#show nve vni 10100 detail
Interface  VNI        Multicast-group  VNI state  Mode  VLAN  cfg vrf
nve1       10100      N/A              Up         L2CP  100   CLI N/A

L2CP VNI IRB state: IPv4 down, IPv6 down
VNI IRB down reason:
BDI's VRF un-configured

L2CP VNI local VTEP info:
VLAN: 100
SVI if handler: 0x55
Local VTEP: 192.168.255.101
Local routing: Disabled

VNI Detailed statistics:
   Pkts In   Bytes In   Pkts Out  Bytes Out
        22       1552         64       7176
C9300-1#

C9300-1#show nve vni 10101 detail
Interface  VNI        Multicast-group  VNI state  Mode  VLAN  cfg vrf
nve1       10101      N/A              Up         L2CP  101   CLI N/A

L2CP VNI IRB state: IPv4 down, IPv6 down
VNI IRB down reason:
BDI's VRF un-configured

L2CP VNI local VTEP info:
VLAN: 101
SVI if handler: 0x56
Local VTEP: 192.168.255.101
Local routing: Disabled

VNI Detailed statistics:
   Pkts In   Bytes In   Pkts Out  Bytes Out
        13        936         25       2550
C9300-1#

5.8 MAC/IP：ローカルとリモートの next hop を見る

VLAN 100 の疑似端末 192.168.33.2 の MAC/IP 経路には、両台でローカルの Po36 と相手 VTEP が表示されています。L2route の詳細では、Producer Name が L2VPN の経路は Po36:100、BGP の経路は相手 VTEP を next hop とし、MAC/IP のリモート経路には proxy が表示されています。

確認は MAC/IP 学習 → EVPN DB → BGP Type 2 → L2 FIB／FED の順で対応させます。1つのテーブルの行数だけで全体の成否を判定しません。

MAC/IP：両台の EVI 別端末情報

MAC/IP.txt

C9300-1#show l2vpn evpn mac ip evi 100
IP Address                              EVI   VLAN  MAC Address    Next Hop(s)
--------------------------------------- ----- ----- -------------- -----------
192.168.33.2                            100   100   0200.0000.0002 Po36:100
                                                                   192.168.255.102
C9300-1#

C9300-1#show l2vpn evpn mac ip evi 101
IP Address                              EVI   VLAN  MAC Address    Next Hop(s)
--------------------------------------- ----- ----- -------------- -----------
C9300-1#

C9300-2#show l2vpn evpn mac ip evi 100
IP Address                              EVI   VLAN  MAC Address    Next Hop(s)
--------------------------------------- ----- ----- -------------- -----------
192.168.33.2                            100   100   0200.0000.0002 Po36:100
                                                                   192.168.255.101
C9300-2#

C9300-2#show l2vpn evpn mac ip evi 101
IP Address                              EVI   VLAN  MAC Address    Next Hop(s)
--------------------------------------- ----- ----- -------------- -----------
C9300-2#

EVPN データベース：Producer・proxy・Next Hop（#1）

EVPN データベース.txt

C9300-1#show l2route evpn summary
Object           Best   Static      BGP    L2VPN      Total
------------ -------- -------- -------- -------- ----------
TOPOLOGY            0        0        0        2          2
MAC                 0        2        1        1          4
IMET                0        0        2        2          4
ES                  0        0        1        1          2
EAD per-EVI         0        2        0        0          2
EAD per-ES          0        0        1        1          2
MAC_IP              0        0        1        1          2
Peer                0        0        3        0          3
DG                  0        0        0        0          0
SMET                0        0        0        0          0
MC-ROUTE            4        0        0        0          4
MC-JOIN-SYNC        0        0        0        0          0
MC-LEAVE-SYN        0        0        0        0          0
Total               4        4        9        6         23
Valid Clients Bitmap: 00000007
C9300-1#

C9300-1#show l2route evpn mac detail
EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            Static
MAC Address:              0200.0000.00d4
Num of MAC IP Route(s):   0
Sequence Number:          0
ESI:                      0102.0000.0000.9900.6300
Flags:                    B()
Next Hop(s):              Po36:100

EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            Static
MAC Address:              0200.0000.0002
Num of MAC IP Route(s):   0
Sequence Number:          0
ESI:                      0102.0000.0000.9900.6300
Flags:                    B(Brm)
Next Hop(s):              Po36:100

EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            BGP
MAC Address:              0200.0000.0002
Num of MAC IP Route(s):   1
Sequence Number:          0
ESI:                      0102.0000.0000.9900.6300
Flags:                    Int(Brm)
Next Hop(s):              V:10100 192.168.255.102
MAC Orig Next Hop(s):     None

EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            L2VPN
MAC Address:              0200.0000.0002
Num of MAC IP Route(s):   1
Sequence Number:          0
ESI:                      0102.0000.0000.9900.6300
Flags:                    Int(Brm)
Next Hop(s):              Po36:100
C9300-1#

C9300-1#show l2route evpn mac ip detail
EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            BGP
MAC Address:              0200.0000.0002
Host IP:                  192.168.33.2
Sequence Number:          0
Label 2:                  0
ESI:                      0102.0000.0000.9900.6300
Subnet Slice Size:        0
Subnet Slices (bitmask):  0
MAC Route Flags:          Int(Brm)
Next Hop(s):              V:10100 192.168.255.102(proxy)

EVPN Instance:            100
Ethernet Tag:             0
Producer Name:            L2VPN
MAC Address:              0200.0000.0002
Host IP:                  192.168.33.2
Sequence Number:          0
Label 2:                  0
ESI:                      0102.0000.0000.9900.6300
Subnet Slice Size:        0
Subnet Slices (bitmask):  0
MAC Route Flags:          Int(Brm)
Next Hop(s):              Po36:100
C9300-1#

MAC テーブルと Anycast Gateway ARP

MAC テーブルと Anycast Gateway ARP.txt

C9300-1#show mac address-table vlan 100
Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
 100    0000.5e00.0101    STATIC      Vl100
 100    0200.0000.00d1    STATIC      Vl100
 100    0200.0000.00d4    DYNAMIC     Po36
 100    0200.0000.0002    DYNAMIC     Po36
Total Mac Addresses for this criterion: 4
C9300-1#

C9300-1#show mac address-table vlan 101
Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
 101    0000.5e00.0101    STATIC      Vl101
 101    0200.0001.9bc1    STATIC      Vl101
Total Mac Addresses for this criterion: 2
C9300-1#

C9300-1#show ip arp vlan 100
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  192.168.33.1            -   0000.5e00.0101  ARPA   Vlan100
Internet  192.168.33.2            0   0200.0000.0002  ARPA   Vlan100
C9300-1#

C9300-1#show ip arp vlan 101
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  192.168.34.1            -   0000.5e00.0101  ARPA   Vlan101
C9300-1#

C9300-2#show mac address-table vlan 100
Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
 100    0000.5e00.0101    STATIC      Vl100
 100    0200.0000.00e6    DYNAMIC     Po36
 100    0200.0000.0002    DYNAMIC     Po36
 100    0200.0000.00a1    STATIC      Vl100
Total Mac Addresses for this criterion: 4
C9300-2#

C9300-2#show mac address-table vlan 101
Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
 101    0000.5e00.0101    STATIC      Vl101
 101    0200.0001.b2c1    STATIC      Vl101
Total Mac Addresses for this criterion: 2
C9300-2#

C9300-2#show ip arp vlan 100
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  192.168.33.1            -   0000.5e00.0101  ARPA   Vlan100
Internet  192.168.33.2            0   0200.0000.0002  ARPA   Vlan100
C9300-2#

C9300-2#show ip arp vlan 101
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  192.168.34.1            -   0000.5e00.0101  ARPA   Vlan101
C9300-2#

L2 FIB：ローカル BD_PORT と VXLAN_REP（#1）

L2 FIB.txt

C9300-1#show l2fib bridge-domain 100 detail
Bridge Domain : 100
  Reference Count : 10
  Replication ports count : 3
  Unicast Address table size : 0
  IP Multicast Prefix table size : 2

  Flood List Information :
    Olist: 1124, Ports: 2

  Port Information :
    BD_PORT   Po36:100
    VXLAN_REP PL:315(1) T:VXLAN_REP [IR]10100:192.168.255.102
    VXLAN_REP PL:335(1) T:VXLAN_REP [IET]10100:192.168.255.102

  IP Multicast Prefix table information :
    Source: *, Group: *, IIF: Null, Adjacency: Olist: 6328, Ports: 1
    Source: ::, Group: ::, IIF: Null, Adjacency: Olist: 6329, Ports: 1
C9300-1#

C9300-1#show l2fib bridge-domain 101 detail
Bridge Domain : 101
  Reference Count : 10
  Replication ports count : 3
  Unicast Address table size : 0
  IP Multicast Prefix table size : 2

  Flood List Information :
    Olist: 1125, Ports: 2

  Port Information :
    BD_PORT   Po36:101
    VXLAN_REP PL:316(1) T:VXLAN_REP [IR]10101:192.168.255.102
    VXLAN_REP PL:336(1) T:VXLAN_REP [IET]10101:192.168.255.102

  IP Multicast Prefix table information :
    Source: *, Group: *, IIF: Null, Adjacency: Olist: 6330, Ports: 1
    Source: ::, Group: ::, IIF: Null, Adjacency: Olist: 6331, Ports: 1
C9300-1#

FED の MATM も、L2 overlay ガイドに掲載されている確認コマンドです。以下は対象 VLAN の登録状況を確認した出力です。FED のソフトウェア管理テーブルだけで、障害切替中の全パケットの ASIC 転送を測定したことにはなりません。

FED：VLAN 100 の MATM 登録（#1）

FED.txt

C9300-1#show platform software fed switch active matm macTable vlan 100
VLAN   MAC                   Type  Seq#    EC_Bi  Flags  machandle           siHandle            riHandle            diHandle              *a_time  *e_time  ports                                                         Con
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
100    0000.5e00.0101      0x8002       0      0     64  0x7b5c18b85258      0x7b5c18e37ae8      0x0                 0x5234                      0        0  Vlan100                                                       Yes
100    0200.0000.00d1      0x8002       0      0     64  0x7b5c18b6cb68      0x7b5c18e37ae8      0x0                 0x0                         0        0  Vlan100                                                       Yes
100    0200.0000.00d4         0x1      20      2      0  0x7b5c18e80148      0x7b5c18e76688      0x0                 0x7b5c18e6e628            300        3  Port-channel36                                                Yes
100    0200.0000.0002         0x1      21      2      0  0x7b5c18eaedb8      0x7b5c18e75728      0x0                 0x7b5c18e6e628            300       28  Port-channel36                                                Yes
Total Mac number of addresses:: 4
C9300-1#

5.9 Anycast Gateway・SVI・DHCP の現状

両台とも VLAN 100／101 の SVI は up/up です。両台の ARP で共通の Gateway IP／MAC を確認できます。今回、show l2vpn evpn default-gateway detail の表示は両台とも空でした。VLAN 101 は SVI と VNI が Up でも、現在は端末の MAC/IP 学習がありません。学習なしをコントロールプレーン故障と即断せず、端末の有無・接続 VLAN・実トラフィックを確認します。

Gateway DB：今回の両実機では表示なし

Gateway DB.txt

C9300-1#show l2vpn evpn default-gateway detail

C9300-1#

C9300-2#show l2vpn evpn default-gateway detail

C9300-2#

SVI：IP と up/up の関連行抜粋

SVI.txt

C9300-1#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
Vlan100                192.168.33.1    YES NVRAM  up                    up
Vlan101                192.168.34.1    YES NVRAM  up                    up
nve1                   unassigned      YES unset  up                    up
Loopback0              192.168.255.101 YES NVRAM  up                    up
C9300-1#

C9300-2#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
Vlan100                192.168.33.1    YES NVRAM  up                    up
Vlan101                192.168.34.1    YES NVRAM  up                    up
nve1                   unassigned      YES unset  up                    up
Loopback0              192.168.255.102 YES NVRAM  up                    up
C9300-2#

DHCP relay 設定とローカル pool の確認

DHCP relay 設定とローカル pool の確認.txt

C9300-1#show running-config interface Vlan100
Building configuration...

Current configuration : 167 bytes
!
interface Vlan100
 description ANYCAST_GATEWAY_VLAN100
 ip address 192.168.33.1 255.255.255.0
 ip helper-address 192.168.64.16
 ip helper-address 192.168.64.17
end
C9300-1#

C9300-1#show running-config interface Vlan101
Building configuration...

Current configuration : 167 bytes
!
interface Vlan101
 description ANYCAST_GATEWAY_VLAN101
 ip address 192.168.34.1 255.255.255.0
 ip helper-address 192.168.64.16
 ip helper-address 192.168.64.17
end
C9300-1#

C9300-1#show ip dhcp pool

C9300-1#

C9300-2#show running-config interface Vlan100
Building configuration...

Current configuration : 167 bytes
!
interface Vlan100
 description ANYCAST_GATEWAY_VLAN100
 ip address 192.168.33.1 255.255.255.0
 ip helper-address 192.168.64.16
 ip helper-address 192.168.64.17
end
C9300-2#

C9300-2#show running-config interface Vlan101
Building configuration...

Current configuration : 167 bytes
!
interface Vlan101
 description ANYCAST_GATEWAY_VLAN101
 ip address 192.168.34.1 255.255.255.0
 ip helper-address 192.168.64.16
 ip helper-address 192.168.64.17
end
C9300-2#

C9300-2#show ip dhcp pool

C9300-2#

5.10 上位ルーティング：EVPN AF と IPv4 unicast AF を分ける

上位 MX は AS 64512、両 C9300 は AS 65100 です。両台とも MX への IPv4 BGP セッションが Established、VLAN 100／101 の /24 を広告しています。
一方、現在の PL-FROM-MX は全 prefix を deny しており、C9300 の出口は 192.168.32.1 向けの static default route です。受信 prefix 0 でもセッション自体は成立しています。
MX 側の best path／weight／NAT の現在値は今回 MX にアクセスして確認したものではないため、ここではスイッチ側の事実だけを示します。

C9300-1：上位向け BGP と経路フィルター（関連行抜粋）

C9300-1-upstream.conf

router bgp 65100
 bgp router-id interface Loopback0
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 192.168.32.1 remote-as 64512
 neighbor 192.168.32.1 description MERAKI_MX
 neighbor 192.168.32.1 timers 10 30
 neighbor 192.168.255.102 remote-as 65100
 neighbor 192.168.255.102 description C9300-2_EVPN
 neighbor 192.168.255.102 update-source Loopback0
 neighbor 192.168.255.102 fall-over host-route
 !
 address-family ipv4
  network 192.168.33.0
  network 192.168.34.0
  neighbor 192.168.32.1 activate
  neighbor 192.168.32.1 prefix-list PL-FROM-MX in
  neighbor 192.168.32.1 prefix-list PL-TO-MX out
 exit-address-family
 !
 address-family l2vpn evpn
  neighbor 192.168.255.102 activate
  neighbor 192.168.255.102 send-community both
 exit-address-family
!
ip prefix-list PL-FROM-MX seq 10 deny 0.0.0.0/0 le 32
ip prefix-list PL-TO-MX seq 10 permit 192.168.33.0/24
ip prefix-list PL-TO-MX seq 20 permit 192.168.34.0/24
!
ip route 0.0.0.0 0.0.0.0 192.168.32.1

C9300-2：上位向け BGP と経路フィルター（関連行抜粋）

C9300-2-upstream.conf

router bgp 65100
 bgp router-id interface Loopback0
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 192.168.32.1 remote-as 64512
 neighbor 192.168.32.1 description MERAKI_MX
 neighbor 192.168.32.1 timers 10 30
 neighbor 192.168.255.101 remote-as 65100
 neighbor 192.168.255.101 description C9300-1_EVPN
 neighbor 192.168.255.101 update-source Loopback0
 neighbor 192.168.255.101 fall-over host-route
 !
 address-family ipv4
  network 192.168.33.0
  network 192.168.34.0
  neighbor 192.168.32.1 activate
  neighbor 192.168.32.1 prefix-list PL-FROM-MX in
  neighbor 192.168.32.1 prefix-list PL-TO-MX out
 exit-address-family
 !
 address-family l2vpn evpn
  neighbor 192.168.255.101 activate
  neighbor 192.168.255.101 send-community both
 exit-address-family
!
ip prefix-list PL-FROM-MX seq 10 deny 0.0.0.0/0 le 32
ip prefix-list PL-TO-MX seq 10 permit 192.168.33.0/24
ip prefix-list PL-TO-MX seq 20 permit 192.168.34.0/24
!
ip route 0.0.0.0 0.0.0.0 192.168.32.1

上位：IPv4 BGP・広告 /24・static default

上位.txt

C9300-1#show bgp ipv4 unicast summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 35, main routing table version 35
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.32.1    4        64512   35407   32534       35    0    0 3d14h           0
C9300-1#

C9300-1#show bgp ipv4 unicast neighbors 192.168.32.1 advertised-routes
BGP table version is 35, local router ID is 192.168.255.101
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
              t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>   192.168.33.0     0.0.0.0                  0         32768 i
 *>   192.168.34.0     0.0.0.0                  0         32768 i

Total number of prefixes 2
C9300-1#

C9300-1#show ip route 0.0.0.0
Routing entry for 0.0.0.0/0, supernet
  Known via "static", distance 1, metric 0, candidate default path
  Routing Descriptor Blocks:
  * 192.168.32.1
      Route metric is 0, traffic share count is 1
C9300-1#

C9300-2#show bgp ipv4 unicast summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 23, main routing table version 23
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.32.1    4        64512   35403   32555       23    0    0 3d14h           0
C9300-2#

C9300-2#show bgp ipv4 unicast neighbors 192.168.32.1 advertised-routes
BGP table version is 23, local router ID is 192.168.255.102
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
              t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>   192.168.33.0     0.0.0.0                  0         32768 i
 *>   192.168.34.0     0.0.0.0                  0         32768 i

Total number of prefixes 2
C9300-2#

C9300-2#show ip route 0.0.0.0
Routing entry for 0.0.0.0/0, supernet
  Known via "static", distance 1, metric 0, candidate default path
  Routing Descriptor Blocks:
  * 192.168.32.1
      Route metric is 0, traffic share count is 1
C9300-2#

6. Po48 のメンバーを停止して確認する

6.1 トラフィックと試験条件

TEST-CE は GRT と別の VRF です。送信元 192.168.33.2 から外部へ ping すると、Po99 → native VLAN 100 → Anycast Gateway → 上位出口のトラフィックを発生させられます。

送信元	宛先	確認すること
#1 TEST-CE / 192.168.33.2	8.8.8.8、8.8.4.4	CE 側 LACP・VLAN 100・Anycast Gateway・上位出口
#1 Loopback0 / 192.168.255.101	#2 Loopback0 / 192.168.255.102	対向 VTEP への underlay 到達性
#2 Loopback0 / 192.168.255.102	#1 Loopback0 / 192.168.255.101	逆方向の underlay 到達性

外部向け ICMP はローカル SVI と上位出口で完結する経路も使えます。外部 ping だけでは inter-ES の VXLAN 転送は確認できません。Loopback 間の ping も underlay の試験です。独立した CE と相手側にしかない端末を用意する VXLAN 転送試験は別途必要です。

試験時の Po48 は BFD なし、IS-IS・BGP fall-over host-route・core-tracking を使用。両台の EtherChannel ハッシュは src-dst-mixed-ip-port です。Gi47／Gi48 の LACP は両端とも fast／active です。

6.2 試験方法

両台の Po48 が RU、Gi47／Gi48 が P、IS-IS・EVPN が Up であることを確認。
各ケースの操作前に4宛先へ5回ずつ ping。
各宛先へ別 SSH セッションから repeat 1 / timeout 1 の ping を、0.5秒周期を目安に継続。
#1・#2 それぞれの Gi47／Gi48 を1本ずつ shutdown。残りの1本が P のまま Po48 が RU であることを確認。
停止中の経路・core-tracking・IS-IS・EVPN を採取し、4宛先へ5回ずつ ping。
no shutdown 後に全メンバー・経路・疎通を確認してから、次のケースへ進む。

受信待ちが発生した ping は周期が延びます。サンプリングした ICMP の成功率を、サブ秒単位の収束時間に換算する試験ではありません。6.3 の片系停止試験では、Gi47／Gi48 を同時には停止していません。

停止・復旧操作：各スイッチで対象ポートを1本ずつ実施

single-member-test.conf

configure terminal
interface GigabitEthernet1/0/47
 shutdown
end
! Collect state and test traffic, then restore.
configure terminal
interface GigabitEthernet1/0/47
 no shutdown
end
! Repeat separately for Gi1/0/48, and for the other switch.

周期 ICMP：送信元と宛先

sampled-icmp.txt

! C9300-1
ping vrf TEST-CE 8.8.8.8 source 192.168.33.2 repeat 1 timeout 1
ping vrf TEST-CE 8.8.4.4 source 192.168.33.2 repeat 1 timeout 1
ping 192.168.255.102 source Loopback0 repeat 1 timeout 1
! C9300-2
ping 192.168.255.101 source Loopback0 repeat 1 timeout 1
! Fixed checks use repeat 5 instead of repeat 1.

6.3 実測結果

実施日時は 2026-10-20 22:10:54〜22:13:09 JST、合計 4ケースです。各ケースの操作前・停止中・復旧後に実施した固定 ping は、4宛先すべて 5/5。片系停止中も IS-IS 隣接と EVPN セッションを維持し、Core Isolation は No でした。

周期 ICMP は固定 ping と分け、操作前から復旧後までの各ケース全体を集計しています。各欄は 成功/送信 です。

停止対象	周回	8.8.8.8	8.8.4.4	#1 → #2 VTEP	#2 → #1 VTEP
#1 Gi47	1	47/47	58/58	56/56	55/55
#1 Gi48	1	49/49	57/57	58/58	60/60
#2 Gi47	1	47/47	47/47	47/47	47/47
#2 Gi48	1	48/48	48/48	45/45	51/51

今回の周期 ICMP サンプルでは欠落を観測しませんでした。固定 ping の成功と IS-IS／EVPN 隣接の維持を確認していますが、無瞬断を保証する結果ではありません。

#1 Gi47 停止中：両台の LACP・IGP・core-tracking・EVPN・経路

member-test.txt

C9300-1#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 4
Number of aggregators:           4

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(D)     Gi1/0/48(P)
C9300-1#

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2     L2   Po48          192.168.255.2   UP    23       58
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:8
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 174, main routing table version 174
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100    5732    5751      174    0    0 3d13h           5
C9300-1#

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:41:19 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:41:19 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-2#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 3
Number of aggregators:           3

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(D)     Gi1/0/48(P)
C9300-2#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1     L2   Po48          192.168.255.1   UP    24       5A
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:5
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 189, main routing table version 189
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100    5751    5732      189    0    0 3d13h           5
C9300-2#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:41:22 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:41:22 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

#1 Gi48 停止中：両台の LACP・IGP・core-tracking・EVPN・経路

member-test.txt

C9300-1#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 4
Number of aggregators:           4

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(D)
C9300-1#

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2     L2   Po48          192.168.255.2   UP    27       58
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:8
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 174, main routing table version 174
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100    5732    5751      174    0    0 3d13h           5
C9300-1#

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:41:56 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:41:56 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-2#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 3
Number of aggregators:           3

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(D)
C9300-2#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1     L2   Po48          192.168.255.1   UP    21       5A
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:5
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 189, main routing table version 189
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100    5751    5733      189    0    0 3d13h           5
C9300-2#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:42:00 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:42:00 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

#2 Gi47 停止中：両台の LACP・IGP・core-tracking・EVPN・経路

member-test.txt

C9300-1#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 4
Number of aggregators:           4

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(D)     Gi1/0/48(P)
C9300-1#

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2     L2   Po48          192.168.255.2   UP    22       58
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:8
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 174, main routing table version 174
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100    5733    5752      174    0    0 3d13h           5
C9300-1#

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:42:34 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:42:34 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-2#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 3
Number of aggregators:           3

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(D)     Gi1/0/48(P)
C9300-2#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1     L2   Po48          192.168.255.1   UP    23       5A
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:5
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 189, main routing table version 189
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100    5752    5733      189    0    0 3d13h           5
C9300-2#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:42:34 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:42:34 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

#2 Gi48 停止中：両台の LACP・IGP・core-tracking・EVPN・経路

member-test.txt

C9300-1#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 4
Number of aggregators:           4

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(D)
C9300-1#

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2     L2   Po48          192.168.255.2   UP    28       58
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:8
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 174, main routing table version 174
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100    5734    5752      174    0    0 3d13h           5
C9300-1#

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:43:01 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:43:01 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-2#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 3
Number of aggregators:           3

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(D)
C9300-2#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1     L2   Po48          192.168.255.1   UP    28       5A
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:5
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 189, main routing table version 189
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100    5752    5734      189    0    0 3d13h           5
C9300-2#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:43:01 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:43:01 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

6.4 fall-over host-route：/32 の喪失と全リンク停止を確認する

本節は 両台で fall-over host-route 有効、Po48 の BFD 未設定の条件です。経路監視の効果を切り分けるため、物理リンクを残して /32 の広告だけを止める試験と、Po48 全体を止める試験を実施しました。

6.4.1 Po48 を Up に保ったまま、対向 /32 の広告を停止する

#2 の IS-IS から Loopback0 の広告を一時的に外します。Loopback0 の IP アドレスと Po48 は維持します。#1 が対向 192.168.255.102/32 を失ったときに、上位 MX 向けの static default が残っていても EVPN BGP が停止することを確認します。

経路監視試験の操作：#2 の Loopback0 広告を停止・復元

host-route-test.conf

! C9300-2: temporarily withdraw the Loopback0 prefix from IS-IS.
configure terminal
router isis UNDERLAY
 no passive-interface Loopback0
end
! Collect RIB, BGP, ES, and physical-link state, then restore.
configure terminal
router isis UNDERLAY
 passive-interface Loopback0
end

広告停止中の観測	#1	#2
対向 Loopback /32	なし	あり
上位向け static default	あり	あり
EVPN BGP	Idle	Established（受信 5）
ES Core Isolation	No	No
Po48／IS-IS	RU・両メンバー P／UP	RU・両メンバー P／UP
BFD	セッションなし	セッションなし

Po48 の2本と IS-IS 隣接が維持され、#1 の default route が残っている状態でも、対向 /32 の喪失で BGP セッションが停止しました。BGP neighbor 詳細には Last reset ... due to Route to peer lost が記録されています。表は各装置で逐次採取したローカル状態です。#2 側には #1 の /32 が残り、採取時の BGP 表示は Established、両台の Core Isolation は No でした。BGP の経路監視と ES の孤立保護は役割が異なるため、それぞれの状態を照合します。

対向 /32 広告停止中：Po48 Up・default 残存と BGP 停止

fallover-test.txt

C9300-1#show ip route 192.168.255.102
% Subnet not in table
C9300-1#

C9300-1#show ip route 0.0.0.0
Routing entry for 0.0.0.0/0, supernet
  Known via "static", distance 1, metric 0, candidate default path
  Routing Descriptor Blocks:
  * 192.168.32.1
      Route metric is 0, traffic share count is 1
C9300-1#

C9300-1#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 4
Number of aggregators:           4

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
C9300-1#

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2     L2   Po48          192.168.255.2   UP    25       58
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 182, main routing table version 182
5 network entries using 1960 bytes of memory
5 path entries using 1200 bytes of memory
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100       0       0        1    0    0 00:00:00 Idle
C9300-1#

C9300-1#show bgp l2vpn evpn neighbors 192.168.255.102
BGP neighbor is 192.168.255.102,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Idle, down for 00:00:01
  Route to peer address reachability Up: 25; Down: 0
  Last reset 00:00:01, due to Route to peer lost of session 1
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:8
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101
C9300-1#

C9300-1#show bfd neighbors details

C9300-1#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:43:31 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:43:31 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

C9300-2#show ip route 0.0.0.0
Routing entry for 0.0.0.0/0, supernet
  Known via "static", distance 1, metric 0, candidate default path
  Routing Descriptor Blocks:
  * 192.168.32.1
      Route metric is 0, traffic share count is 1
C9300-2#

C9300-2#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 3
Number of aggregators:           3

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
C9300-2#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1     L2   Po48          192.168.255.1   UP    25       5A
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 189, main routing table version 189
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100    5753    5734      189    0    0 3d13h           5
C9300-2#

C9300-2#show bgp l2vpn evpn neighbors 192.168.255.101
BGP neighbor is 192.168.255.101,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Established, up for 3d13h
  Last read 00:00:23, last write 00:00:40, hold time is 180, keepalive interval is 60 seconds
  Route to peer address reachability Up: 25; Down: 0
  Last reset never
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:5
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show bfd neighbors details

C9300-2#

Loopback0 の広告を戻した後は、#1 で対向 /32 の再学習と EVPN BGP の再確立、両台で ES の通常状態と4宛先への固定 ping（すべて5/5）を確認しました。

対向 /32 広告の復元後：経路・BGP・ES

fallover-test.txt

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:00:14 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:00:14 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 190, main routing table version 190
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100      10      10      190    0    0 00:00:01        5
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:8
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:43:50 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:43:50 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 205, main routing table version 205
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100      10      10      205    0    0 00:00:04        5
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:5
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

6.4.2 Po48 全体を停止する

両端間のリンクを止めるため、#1 の Gi47／Gi48 を同時に shutdown します。管理アクセスに使う Gi1/0/1 は維持します。追跡対象が Po48 のみのため、両スイッチがすべての追跡対象インターフェイスを同時に失う試験です。上位へ対向 Loopback の代替経路を用意した構成とは条件が異なります。

項目	操作前	Gi47／Gi48 停止中	復旧後
Po48	RU、2メンバー P	RD、2メンバー D	RU、2メンバー P
core-tracking の Po48	up/up	down/down	up/up
対向 Loopback /32	IS-IS 経路あり	経路なし	IS-IS 経路あり
BFD	セッションなし	セッションなし	セッションなし
ES の Core Isolation	No	Yes (error disable)	No
ES State	Ready	Disabled (reason: core isolated)	Ready
Po36	SU	SD	SU

停止中の BGP peer	観測状態
C9300-1	Idle
C9300-2	Idle

対向 /32 の消失に伴う BGP の停止と、ES の Core Isolation を確認しました。リンク復旧後は、Gi36 や Po36 に手動の shutdown／no shutdown を入れずに、IGP 経路・BGP・LACP・ES が自動復帰しています。

採取時刻（JST）	観測
22:13:40.000	操作前：対向 /32 あり、BGP Established、Core Isolation No
22:13:47.582	停止中：対向 /32 なし、BGP 停止、Core Isolation Yes
22:15:06.924	復旧確認：対向 /32・BGP・ES が復帰

BGP neighbor 詳細には事前の Hold time 180秒・Keepalive 60秒を併記しています。今回の BGP 停止は Hold Timer の満了を待つ動作ではありません。

上の時刻は CLI の採取時刻です。サブ秒の検出・転送収束時間を精密に測定した結果ではありません。 また、障害の検出・経路切替と、復旧時の ES 再立ち上げ・LACP 復帰に要する時間は区別します。今回の全追跡対象の停止は両スイッチの保護動作を確認する条件であり、一方の装置を経由して通信を継続する試験ではありません。

両系停止前：対向 /32・BGP・追跡対象と ES

fallover-test.txt

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:00:20 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:00:20 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 190, main routing table version 190
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100      10      10      190    0    0 00:00:07        5
C9300-1#

C9300-1#show bgp l2vpn evpn neighbors 192.168.255.102
BGP neighbor is 192.168.255.102,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Established, up for 00:00:08
  Last read 00:00:08, last write 00:00:08, hold time is 180, keepalive interval is 60 seconds
  Route to peer address reachability Up: 26; Down: 0
  Last reset 00:00:24, due to BGP Notification received, Connection Collision Resolution
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:8
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:43:55 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:43:55 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 205, main routing table version 205
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100      10      10      205    0    0 00:00:09        5
C9300-2#

C9300-2#show bgp l2vpn evpn neighbors 192.168.255.101
BGP neighbor is 192.168.255.101,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Established, up for 00:00:10
  Last read 00:00:10, last write 00:00:10, hold time is 180, keepalive interval is 60 seconds
  Route to peer address reachability Up: 25; Down: 0
  Last reset 00:00:22, due to Peer closed the session of session 1
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:5
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

両系停止中：経路・BGP reset 理由・core-tracking・ES

fallover-test.txt

C9300-1#show ip route 192.168.255.102
% Subnet not in table
C9300-1#

C9300-1#show ip route 0.0.0.0
Routing entry for 0.0.0.0/0, supernet
  Known via "static", distance 1, metric 0, candidate default path
  Routing Descriptor Blocks:
  * 192.168.32.1
      Route metric is 0, traffic share count is 1
C9300-1#

C9300-1#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 4
Number of aggregators:           4

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RD)        LACP        Gi1/0/47(D)     Gi1/0/48(D)
C9300-1#

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 203, main routing table version 203
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100       0       0        1    0    0 00:00:02 Idle
C9300-1#

C9300-1#show bgp l2vpn evpn neighbors 192.168.255.102
BGP neighbor is 192.168.255.102,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Idle, down for 00:00:03
  Route to peer address reachability Up: 27; Down: 0
  Last reset 00:00:03, due to Route to peer lost of session 1
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         down                   down
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    64563
  State:                  Disabled (reason: core isolated)
  Encapsulation:          none
  Ordinal:                Not available
  Core Isolation:         Yes (error disable)
  Forwarder List:
C9300-1#

C9300-1#show bfd neighbors details

C9300-1#

C9300-2#show ip route 192.168.255.101
% Subnet not in table
C9300-2#

C9300-2#show ip route 0.0.0.0
Routing entry for 0.0.0.0/0, supernet
  Known via "static", distance 1, metric 0, candidate default path
  Routing Descriptor Blocks:
  * 192.168.32.1
      Route metric is 0, traffic share count is 1
C9300-2#

C9300-2#show etherchannel 48 summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 3
Number of aggregators:           3

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
48     Po48(RD)        LACP        Gi1/0/47(D)     Gi1/0/48(D)
C9300-2#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 218, main routing table version 218
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100       0       0        1    0    0 00:00:03 Idle
C9300-2#

C9300-2#show bgp l2vpn evpn neighbors 192.168.255.101
BGP neighbor is 192.168.255.101,  remote AS 65100, internal link
 Fall over configured for session
 Fall over with host route loss configured for session
  BGP state = Idle, down for 00:00:04
  Route to peer address reachability Up: 26; Down: 0
  Last reset 00:00:04, due to Route to peer lost of session 1
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         down                   down
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    64563
  State:                  Disabled (reason: core isolated)
  Encapsulation:          none
  Ordinal:                Not available
  Core Isolation:         Yes (error disable)
  Forwarder List:
C9300-2#

C9300-2#show bfd neighbors details

C9300-2#

全リンク復旧後：経路・BGP・Core Isolation の解除

fallover-test.txt

C9300-1#show ip route 192.168.255.102
Routing entry for 192.168.255.102/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.2 on Port-channel48, 00:00:54 ago
  Routing Descriptor Blocks:
  * 192.168.255.2, from 192.168.255.102, 00:00:54 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 213, main routing table version 213
10 network entries using 3920 bytes of memory
10 path entries using 2400 bytes of memory
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100       8       8      213    0    0 00:00:53        4
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:9
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-1#show etherchannel 36 summary
Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
36     Po36(SU)        LACP        Gi1/0/36(P)
C9300-1#

C9300-1#show bfd neighbors details

C9300-1#

C9300-2#show ip route 192.168.255.101
Routing entry for 192.168.255.101/32
  Known via "isis", distance 115, metric 10, type level-2
  Redistributing via isis UNDERLAY
  Last update from 192.168.255.1 on Port-channel48, 00:00:59 ago
  Routing Descriptor Blocks:
  * 192.168.255.1, from 192.168.255.101, 00:00:59 ago, via Port-channel48
      Route metric is 10, traffic share count is 1
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 231, main routing table version 231
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100      10       9      231    0    0 00:00:58        5
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:6
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show etherchannel 36 summary
Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
36     Po36(SU)        LACP        Gi1/0/36(P)
C9300-2#

C9300-2#show bfd neighbors details

C9300-2#

この実測から、今回の直結 MH ペアでは BFD を使用せず、物理リンク・IGP・BGP fall-over host-route・EVPN core-tracking を組み合わせた障害検出と孤立保護が成立することを確認できました。物理リンクが Up で、対向 /32 の経路も残る状態での転送障害は今回の試験対象外であり、そのような検出要件があれば BFD の採否を別途判断します。

6.5 追加検証：Port-channel の BFD は 750 ms × 3 の条件を確認する

基本構成では BFD を使用していませんが、追加する場合に押さえたい仕様があります。Catalyst 9300 の IOS XE 26.x IP Routing Command Reference の bfdは、Port-channel 上の BFD に 750 ms × 3 のタイマー制約を記載しています。本ラボでは最小送信間隔 750 ms、最小受信間隔 750 ms、検出倍率 3 を設定して確認しました。BFD 設定ガイドとあわせて、設定できる値・対象 IF の制約・実際の動作値を照合します。

追加検証時の設定：両台の Po48（基本構成への任意の追加）

optional-bfd750.conf

interface Port-channel48
 no ip redirects
 bfd interval 750 min_rx 750 multiplier 3
 bfd echo
 isis bfd

追加検証の項目	結果
実施時刻	2026-10-20 21:30:53〜21:34:53 JST
設定	750 ms／750 ms／multiplier 3、echo 有効
EtherChannel ハッシュ	両台とも src-dst-mixed-ip-port
BGP fall-over host-route	この BFD タイマーの参考測定では未使用
停止・復旧	両台の Gi47／Gi48 を各2回、計8ケース
BFD／IS-IS の Down	0回
操作前・停止中・復旧後の固定 ping	各ケース・4宛先すべて5/5
周期 ICMP：8.8.8.8	401/401
周期 ICMP：8.8.4.4	397/397
周期 ICMP：#1 → #2 VTEP	396/397
周期 ICMP：#2 → #1 VTEP	396/397

以下は 追加検証時の出力です。本節は BFD タイマーの参考測定であり、BFD なし・fall-over host-route 有効の基本構成とは採取条件が異なります。echo interval は 750 ms です。一方、制御パケット側の MinTxInt／MinRxInt はマイクロ秒単位で、出力の 1000000 は1秒を表します。echo と制御パケットの間隔を分けて読みます。show bfd neighbors のコマンドリファレンスも参照できます。750 ms × 3 = 2.25秒という設定上の積を、そのままアプリケーションの復旧時間とは扱いません。周期 ICMP の欠落も表のとおり含めています。

追加検証時：750 ms の echo と登録プロトコル

optional-bfd750-show.txt

C9300-1#show bfd neighbors details
IPv4 Sessions
NeighAddr                              LD/RD         RH/RS     State     Int
192.168.255.2                           1/1          Up        Up        Po48
Session state is UP and using echo function with 750 ms interval.
Session Host: Software
OurAddr: 192.168.255.1
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 1000000, Received Multiplier: 3
Echo Rx Count: 369, Echo Rx Interval (ms) min/max/avg: 568/1274/661 last: 243 ms ago
Echo Tx Count: 370, Echo Tx Interval (ms) min/max/avg: 568/750/659 last: 243 ms ago
Registered protocols: ISIS CEF
Uptime: 00:04:04
C9300-1#

C9300-2#show bfd neighbors details
IPv4 Sessions
NeighAddr                              LD/RD         RH/RS     State     Int
192.168.255.1                           1/1          Up        Up        Po48
Session state is UP and using echo function with 750 ms interval.
Session Host: Software
OurAddr: 192.168.255.2
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 1000000, Received Multiplier: 3
Echo Rx Count: 371, Echo Rx Interval (ms) min/max/avg: 567/1429/660 last: 535 ms ago
Echo Tx Count: 372, Echo Tx Interval (ms) min/max/avg: 567/749/658 last: 535 ms ago
Registered protocols: ISIS CEF
Uptime: 00:04:05
C9300-2#

6.6 復旧後の確認と試験範囲

試験後は全ポートを no shutdown に戻し、Po48 の2メンバー P、IS-IS 隣接1本、BFD セッションなし、EVPN Established、両 peer の fall-over host-route を確認して設定を保存しました。Po36 と TEST-CE Po99 も通常状態です。両台の src-dst-mixed-ip-port は startup-config にも保存しています。

装置の電源断、独立した CE、VLAN 101 の tagged 端末、VXLAN を必ず通る端末間通信、DHCP 更新は別の試験項目です。TEST-CE が #1 と同じ筐体にある点も踏まえて評価します。

復旧確認：Po48・IS-IS・core-tracking・EVPN（関連行抜粋）

復旧確認.txt

C9300-1#show clock detail
22:15:32.461 JST Tue Oct 20 2026
Time source is NTP
C9300-1#

C9300-1#show etherchannel summary
Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
36     Po36(SU)        LACP        Gi1/0/36(P)
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
99     Po99(RU)        LACP        Gi1/0/33(P)     Gi1/0/34(P)
C9300-1#

C9300-1#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-2     L2   Po48          192.168.255.2   UP    29       58
C9300-1#

C9300-1#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-1#

C9300-1#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                0
  Core Isolation:         No
  RD:                     192.168.255.101:9
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-1#

C9300-1#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.101, local AS number 65100
BGP table version is 216, main routing table version 216
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.102 4        65100       9      10      216    0    0 00:01:25        5
C9300-1#

C9300-2#show clock detail
22:15:34.079 JST Tue Oct 20 2026
Time source is NTP
C9300-2#

C9300-2#show etherchannel summary
Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
36     Po36(SU)        LACP        Gi1/0/36(P)
48     Po48(RU)        LACP        Gi1/0/47(P)     Gi1/0/48(P)
C9300-2#

C9300-2#show isis neighbors
Tag UNDERLAY:
System Id       Type Interface     IP Address      State Holdtime Circuit Id
C9300-1     L2   Po48          192.168.255.1   UP    21       5A
C9300-2#

C9300-2#show l2vpn evpn multihoming core-tracking
Core Interface         Status                 Protocol
---------------------- ---------------------- --------
Port-channel48         up                     up
C9300-2#

C9300-2#show l2vpn evpn ethernet-segment detail
EVPN Ethernet Segment ID: 0102.0000.0000.9900.6300
  Local Discriminator:    64548
  Interface:              Po36
  Redundancy mode:        all-active
  DF election wait time:  1 seconds
  Preempt time:           N/A
  Split Horizon label:    0
  State:                  Ready
  Encapsulation:          vxlan
  Ordinal:                1
  Core Isolation:         No
  RD:                     192.168.255.102:6
    Export-RTs:           65100:100 65100:101
  Forwarder List:         192.168.255.101 192.168.255.102
C9300-2#

C9300-2#show bgp l2vpn evpn summary
BGP router identifier 192.168.255.102, local AS number 65100
BGP table version is 231, main routing table version 231
12 network entries using 4704 bytes of memory
13 path entries using 3120 bytes of memory
1 multipath network entries and 2 multipath paths
Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.255.101 4        65100      10       9      231    0    0 00:01:27        5
C9300-2#

7. 出力を読むときに混同しやすい点

見え方	切り分けの考え方
EVI が Established	BGP neighbor、ES、access LAG、MAC/IP、NVE もあわせて確認する
BGP の受信 prefix が0	数値の0と Idle は別。ES アクセスリンクの停止でも経路は変化する
/32 消失時に BGP が停止し ES が Disabled	fall-over host-route の設定、対向 /32、BGP reset 理由、Core Isolation と IF 状態を照合する
Gi36(P)	EtherChannel の bundled。LACP neighbor の Passive フラグとは別
PE-to-CE BUM blocked	その VLAN の non-DF。LAG 全体を使わないという意味ではない
VLAN 101 の MAC/IP が0	現在のラボは VLAN 101 端末未学習。VNI Up と端末通信確認は分ける
NVE 詳細に IRB down	down の対象を読み、SVI/GRT、EVI、L3VNI の有無と疎通を照合する
Multi-home aliasing Disabled	今回は adjacent／proxy MAC/IP を使う non-fabric の設定。Type 1 全体の欠如とは違う
Type 5 がない	この構成では上位 /24 は IPv4 AF で広告し、出口は GRT static default
LACP neighbor の Dev ID が同じ	MH ペアが CE から同じ論理システムに見えているか、ES 状態とあわせて確認する

STP も確認しました。対象 VLAN では「spanning tree instance does not exist」と表示されていますが、running-config の STP global mode は rapid-pvst のままです。この観測から、他の VLAN の STP まで全体で無効にする設定例は作りません。

補助確認：対象 VLAN の STP 表示

補助確認.txt

C9300-1#show spanning-tree vlan 100

Spanning tree instance(s) for vlan 100 does not exist.

C9300-1#

C9300-1#show spanning-tree vlan 101

Spanning tree instance(s) for vlan 101 does not exist.

C9300-1#

C9300-2#show spanning-tree vlan 100

Spanning tree instance(s) for vlan 100 does not exist.

C9300-2#

C9300-2#show spanning-tree vlan 101

Spanning tree instance(s) for vlan 101 does not exist.

C9300-2#

8. ガイド掲載コマンドのチェックリスト

以下は、BFD を使用しない本構成で両台の EVPN・IS-IS・fall-over host-route・core-tracking・LACP を確認するコマンドです。BFD の show は未使用確認と追加検証用です。公式ガイド掲載のコマンドを中心に、必要な補助コマンドを加えています。VLAN／EVI／VNI は本構成の値を指定しています。取得時刻によって学習件数・uptime・カウンタは変わります。

チェックリスト：Non-fabric: Verify / ES

checklist.txt

show l2vpn evpn multihoming core-tracking
show bgp l2vpn evpn summary
show etherchannel summary
show vlan id 100
show vlan id 101
show l2vpn evpn evi 100 detail
show l2vpn evpn evi 101 detail
show l2vpn evpn mac ip evi 100
show l2vpn evpn mac ip evi 101
show ip arp vlan 100
show ip arp vlan 101

チェックリスト：L2 Overlay: Verifying

checklist.txt

show l2vpn evpn summary
show l2vpn evpn evi
show l2vpn evpn capabilities
show l2vpn evpn route-target
show l2vpn evpn memory
show l2vpn evpn mac
show l2vpn evpn peers vxlan
show l2route evpn summary
show l2route evpn mac detail
show l2route evpn mac ip detail
show l2route evpn imet detail
show bgp l2vpn evpn
show bgp l2vpn evpn route-type 2
show bgp l2vpn evpn evi context
show bgp l2vpn evpn evi 100 route-type 3
show bgp l2vpn evpn evi 101 route-type 3
show l2fib bridge-domain 100 detail
show l2fib bridge-domain 101 detail
show nve vni
show nve vni 10100 detail
show nve vni 10101 detail
show nve peers
show mac address-table vlan 100
show mac address-table vlan 101
show platform software fed switch active matm macTable vlan 100
show platform software fed switch active matm macTable vlan 101

チェックリスト：IRB: Gateway verification

checklist.txt

show l2vpn evpn default-gateway detail

チェックリスト：IS-IS / BFD / EtherChannel / supporting routing checks

checklist.txt

show etherchannel 48 summary
show etherchannel 48 detail
show etherchannel load-balance
show lacp internal
show lacp neighbor
show isis neighbors
show isis neighbors detail
show isis protocol
show clns protocol
show isis database
show ip route isis
show bfd neighbors
show bfd neighbors details
show ip route 192.168.255.101
show ip route 192.168.255.102
show ip cef 192.168.255.101 detail
show ip cef 192.168.255.102 detail

本環境で使用する CLI の引数

peer の確認には show l2vpn evpn peers vxlan、L2 FIB の確認には show l2fib bridge-domain 100 detail を使用します。VLAN 101 は bridge-domain に 101 を指定します。

NVE の VNI 詳細は VNI ID を指定した後に detail を付けます。本構成では show nve vni 10100 detail と show nve vni 10101 detail を使用します。

追加資料：capability と import RT（#1）

追加資料.txt

C9300-1#show l2vpn evpn capabilities
EVPN Platform Capabilities
 VLAN-based EVPN Instance: supported
 VLAN-bundle EVPN Instance: not supported
 VLAN-aware EVPN Instance: not supported
 Ingress replication type: supported
 Point-to-multipoint replication type: not supported
 Multipoint-to-multipoint replication type: not supported
 Static replication type: supported
 Per-BD MPLS label allocation mode: not supported
 Per-CE MPLS label allocation mode: not supported
 Per-EVI MPLS label allocation mode: not supported
 Address resolution flooding suppression: supported
 DHCP Relay flooding suppression: not supported
 Protected VLAN: supported
 VLAN configuration mode: supported
 MPLS encapsulation: not supported
 VxLAN encapsulation: supported
 Multi-homing aliasing: supported
 Multi-homing IRB: supported
 VPLS stitching: supported
 VPLS seamless integration: not supported
 Multi-homing all active redundancy mode: supported
 Multi-homing single active redundancy mode: supported
 Ethernet Segment old config model: not supported
 IP local learning: supported
 VPLS stitching single-active dual-homing: supported
 Layer 2 Tenant Routed Multicast IPv4: supported
 Layer 2 Tenant Routed Multicast IPv6: supported
 Layer 2 multicast source specific forwarding: not supported
 VPWS Preferred Path SRTE Policy: not supported
 EVPN VPWS over SRv6: not supported
 Multi-homing device ID: supported
 Multi-homing DF bulk notification: supported
 Subnet slicing: supported
C9300-1#

C9300-1#show l2vpn evpn route-target
Route Target           EVPN Instances
65100:100              100
65100:101              101

C9300-1#

9. 参考資料

本文の実機出力は今回採取したものです。説明・設定項目の照合には以下の一次資料を使用しました。参照日は 2026-10-20。26.x のガイドには複数の更新時点があるため、本記事は将来リリース全般の動作保証を意味しません。