Why am I being disconnected from my Linode after a few minutes of inactivity?

We typically find that connectivity timeouts are a result of a setting in place for the SSH client as opposed to the Linode itself, but there are a couple of things you can do to narrow down the cause and fix this issue. For your Linode, adding a line to /etc/ssh/sshd_config that states ClientAliveInterval 60 should prevent you from seeing a timeout error. The same can be done on your local computer. Both options are described in this article.