So you’re working in putty. And if you’re like me, you have about sessions you’re working on at the same time. You go back to one of your other putty windows and notice you’ve been disconnected. Very frustrating, now you have to log back in. The trick is in enabling keep alive on your puttys “default session. To accomplish that, simply do the following:

Open Putty and go to the “Connection” tab
Under “Sending of null packets to keep session active – Seconds between keepalives (0 to turn off)”, enter a value in the text box. In this example, we do 120 seconds which should be more than enough.
prevent_ssh_timeout_putty_464w_2

Now, lets save Go to “Session” and save this as “Default Settings”.
prevent_ssh_timeout_putty_465w_1

That’s it, now it’s saved in the registry and everytime you open putty, it’ll apply these settings and keep you from getting timed out.