Ssh through another ssh server

This is common need for university. scientific computing cluster or probably all sorts of work place networks too: you need to access the target ssh server from the internal network which in turn requires you to either push through vpn, which can often be a pain to get working, or ssh through another server like so:

ssh-add
ssh workplace-gateway
ssh workplace-sekrit

No more is it necessary, you set up .ssh/config like this:

Host *
    ForwardAgent yes
Host workplace-gateway
    ...
Host workplace-sekrit
    ...
    ProxyCommand ssh -W %h:%p workplace-gateway

and you can just ssh workplace-sekrit from local. The reason I write it up here, is that I don’t have ssh in my dotfiles for some imaginary security reasons, and it’s hard to google, cause the actual recipe is hidden in the first stack-overflow hit.