Description of problem: ssh connections die when left idle over a NAT router (timeout varies but is seldomly configurable for appliance-class devices) Additional info: Please include in the redhat release the "watchdog/heartbeat" patches for openssh... http://www.sc.isc.tohoku.ac.jp/~hgot/sources/openssh-watchdog.html these allow the automatic transmission of occasional SSH protocol NOP packets which keep the connection alive and prevent NAT timeouts and dropped connections. -- stig
hey nalin, can you bump this issue up a notch? being able to preserve connections over NAT (DSL routers, for example) boundaries is really important these days. every time i update redhat/fedora i have to re-do these patches and fork my own rpms. most people probably just suffer repeatedly dropped connections (with screen, perhaps, on the far side so moderate the pain)... all the windows SSH clients i've seen can keep the connection alive, so why can't the main branch?
It seems terribly broken that ssh connections would be dropped just like that because they are idle. That seems like some broken/overly aggressive firewalling.. On another note, aren't there a server side sshd_config options to this (e.g. TCPKeepAlive or ClientAliveInterval spring to mind). Why can't you get your server to set those?
This is implemented in the current openssh-3.9p1 in FC3. ServerAliveInterval, TCPKeepAlive are your friends. See man ssh_config.