Keep SSH connection open

Many home and office routers kill "idle" connections after a certain length of time, forcing you to log in again. From an ISP's point of view this is understandable, but imho it's just annoying to loose a connection when you just went for a coffee and forget to be back in time.
A one-line addition to the end of the client's SSH configuration file (found at /etc/ssh/ssh_config in many systems) can fix this:

ServerAliveInterval 180

That should send a little ping out every three minutes to ensure the connection is kept alive. This tip should work on most OpenSSH servers that allows access to its sshd_config file. Just make sure you close your connection if you really don't use it for some time.