SSH hacks – a little sanity for remote workers
> What are your favorite SSH tips & tricks?    $ ssh -J user1@host1 user_final@host_final

or    $ ssh -J user1@host1,user2@host2 user_final@host_final

Not many people know it, you don't need to launch a SSH within a SSH session - SSH has built-in support of using one SSH server as a proxy to another SSH server. Useful for hacking servers accessing servers behind a firewall, or using your own server as a proxy to bypass a bottleneck in the network.