How to SSH via proxy

On the local machine, create a new host entry in ~/.ssh/config for the remote server.

Host REMOTE_SERVER

The ProxyCommand directive specifies the proxy server and the command to execute from the proxy server (e.g., ssh example.com). To connect to a reverse SSH tunnel from the proxy, the command would be something like nc localhost REMOTE_SERVER_PORT.

    ProxyCommand ssh PROXY_SERVER COMMAND

The Port and User are of the remote server, not the proxy server.

    Port REMOTE_SERVER_PORT
    User REMOTE_USER

If the proxy server and the remote server use different credentials, the ForwardAgent on directive can be used to pass local credentials through the proxy server in order to authenticate to the remote server. In this way, the local private key does not have to be stored on the proxy server.

    ForwardAgent yes

The final command will look something like this:

Host example.com
    ProxyCommand ssh proxyexample.com 'ssh example.com'
    Port 22
    User me
    ForwardAgent yes