SSH to a machine behind firewall

(This post is mostly for myself, because I know I’ll forget the exact syntax next I need it)

I’ve recently discovered that instead of ssh to one machine and then ssh to another machine in the local network, I can configure ssh to start the proxy connection automatically.  For example:

Host example-local-10
    HostName 192.168.0.10
    ProxyCommand ssh example.com nc %h %p 2> /dev/null

Especially useful when working with various tools that just use the ssh transport protocol, like scp or rsync.