Shell Programming and Scripting

It might be that you're being kicked before you hit tab, but your client doesn't notice the connection's broken until it tries to send something.

Hi,

It might also be useful here to know what client you're actually using at your end if it's something other than command-line OpenSSH (product name and version if possible).

One possibility here might be that if you're using an unusual client that doesn't actually send any output to the remote end until an event occurs that necessitates it to be sent (like an end-of-line return, or needing immediate results from a tab complete, say) that time-outs are in fact the issue.

In this situation your session only looks like its alive because your client is really just doing local echos of your own keystrokes, and your apparent immediate disconnect on tab completion happens because in reality your session has already ended.

It's unlikely (to put it mildly), but hey, it's an outside possibility I suppose, if you're using an oddly-behaved client.

Could be a firewall in between that is quietly dropping the connection after a period of inactivity and who does not inform client or server. A client-side keepalive packet could prevent that, as suggested earlier...