If you happen to be stuck behind a corporate firewall with only HTTP proxies for external access, you might still be able to SSH out through them using the built-in
nc on *nix systems.
Sometime when you have two network interfaces (say
eth1) on the client and for some reason there is a need to SSH to the server over a specific a specific interface. By default the primary interface will be used. To use eth1 we just need to add a route:
route add -net 10.75.0.0 netmask 255.255.255.0 gw 192.168.0.1 eth1
The route is removed upon reboot. Use -p to permanently add the route to the table. To delete the route:
route del -net 10.75.0.0 netmask 255.255.255.0 gw 192.168.0.1 eth1
If you’re anything like me, you probably log in and out of a half dozen remote servers (or these days, local virtual machines) on a daily basis. And if you’re even more like me, you have trouble remembering all of the various usernames, remote addresses and command line options for things like specifying a non-standard connection port or forwarding local ports to the remote machine.