I’ve just set up a new Linux box (OpenSuSE 12.3 on VmWare). Now I stated that my SSH shell sessions are disconnected exactly after 20 minutes, clearly with activity. (Putty: “Network error: Software caused connection abort”)

I already set Putty to send keep alives every 64 sec. In sshd_config, I set

ClientAliveInterval 50
ClientAliveCountMax 2

and did a deamon reload. Didn’t help. About two minutes after the link breakdown, ssh reports to /var/log/messages:

… … sshd[…]: Timeout, client not responding.
… … sshd[…]: pam_unix(sshd:session): session closed for user root

I don’t encounter this behaviour when connecting to other virtual machines, so I guess the problem isn’t in the network. Any help is appreciated.