Kuo Kan Liang wrote: > Dear all, > > I have recently reinstalled my server (SL4.1, x86_64). I have > encountered ssh timeout problem again. In the sshd_conf I have > uncommented "TCPKeepAlive yes" and I have set "ClientAliveInterval 60". > But I ketp got kicked out. I forgot what I did in the previous > installation. The network hardware are the same, so there is no change > in external firewall. What can be the problem? I believe the default is 'TCPKeepAlive yes' - so you might want to explicitly set it to 'no'. If you believe it's a network problem, your first step might be to make sure that the in-band keepalive packets (not the TCP out-of-band ones which you are disabling) are flowing. Ssh in with -vv, wait 60 seconds or so. You should see these: debug1: client_input_channel_req: channel 0 rtype keepalive@ openssh.com reply 1 Are you seeing them? Thanks, Matt Cuttler