Nice reference. Reaching target hosts multiple jump-hosts away, and going the wrong way through multiple firewalls segregating those lans, is another use-case

Nice reference. Reaching target hosts multiple jump-hosts away, and going the wrong way through multiple firewalls segregating those lans, is another use-case of tunnels I've found handy. i.e. your_remote_client_host->internet->fw1->lan1->fw2->lan2->fw3->target_host Target_host can be reached by doing tunnel-in-tunnel-in-tunnel-in-tunnel. Each tunnel gets you past one firewall. The final tunnel you can just ssh to fw3 via a local tunnel and a local port on your_remote_client now takes you straight to target_host.