MaxSessionの変更方法

以下エラーメッセージがsecureに出力された場合、Max Sessionの数値を変更する可能性があります。

Received disconnect from 172.22.206.170 port 64269:2: disconnected by server request

MaxSessionsは/etc/ssh/sshd_configにて変更可能です。

# MaxSessions 10
↓
MaxSessions 50

MaxSessionsの説明は、https://cloud6.net/so/ssh/1248050の通りです。

MaxSessions
     Specifies the maximum number of open shell, login or subsystem
     (e.g. sftp) sessions permitted per network connection.  Multiple
     sessions may be established by clients that support connection
     multiplexing.  Setting MaxSessions to 1 will effectively disable
     session multiplexing, whereas setting it to 0 will prevent all
     shell, login and subsystem sessions while still permitting for-
     warding.  The default is 10.

 MaxStartups
     Specifies the maximum number of **concurrent   unauthenticated con-
     nections to the SSH daemon.**  Additional connections will be
     dropped until authentication succeeds or the LoginGraceTime
     expires for a connection.  The default is 10:30:100.

     Alternatively, random early drop can be enabled by specifying the
     three colon separated values ``start:rate:full'' (e.g.
     "10:30:60").  sshd(8) will refuse connection attempts with a
     probability of ``rate/100'' (30%) if there are currently
     ``start'' (10) unauthenticated connections.  The probability
     increases linearly and all connection attempts are refused if the
     number of unauthenticated connections reaches ``full'' (60).

以上