Way to avoid ssh connection timeout & freezing of terminal tab

Question

When I connect via ssh terminal to certain servers, it timeouts and "freezes" the terminal (doesn't accept, doesn't disconnect, can't Ctrl-C to kill the ssh process or anything).

This is in Ubuntu's Gnome-terminal, though it seems to be pausing the terminal input/output, and doesn't affect the operation of the Gnome-terminal software itself. so less a bug with gnome-terminal than an annoying inconsistency with ssh.

So is there a way to prevent regain the terminal from ssh connections that have timed out?

Answer 1

sshd (the server) closes the connection if it doesn't hear anything from the client for a while. You can tell your client to send a sign-of-life signal to the client once in a while.

The configuration for this in the file ~/.ssh/config. To send the signal every four minutes to remotehost, put the following in your ~/.ssh/config.

Host remotehost
  HostName remotehost.com
  ServerAliveInterval 240

This is what I have in my ~/.ssh/config.

To enable it for all hosts use:

Host *
  ServerAliveInterval 240

Also make sure to run chmod 600 ~/.ssh/config, because the config file must not be world-readable.

Answer 2

Press Enter, ~, . one after the other. The section "ESCAPE CHARACTERS" in the ssh man page explains the underlying details.