簡易DHCPサーバ確認

send DHCP Discover

send.py

from scapy.all import Ether, IP, UDP, BOOTP, DHCP, sendp, RandMAC

for _ in range(5):
    mac = str(RandMAC())
    chaddr = "".join([chr(int(x, 16)) for x in mac.split(":")])

    discover = (
        Ether(dst="ff:ff:ff:ff:ff:ff", src=mac, type=0x0800)
        / IP(src="0.0.0.0", dst="255.255.255.255")
        / UDP(dport=67, sport=68)
        / BOOTP(op=1, chaddr=chaddr)
        / DHCP(options=[("message-type", "discover"), ("end")])
    )
    sendp(discover, verbose=0)

recieve DHCP Offer

recv.py

from scapy.all import sniff


def on_dhcp_offer(packet):
    print(packet.summary())


sniff(prn=on_dhcp_offer, filter="udp src port 67", store=0)

filterはBPF syntax。詳細こちら