ssh jump host

title: learning how to do an ssh jump host on tpo

You need to use an ssh jump host to access internal machines at tpo. If you have a recent enough ssh (>= 2016 or so), then you can use the ProxyJump directive. Else, use ProxyCommand. ProxyCommand automatically executes the ssh command on the host to jump to the next host and forward all traffic through.

With recent ssh versions:

Host *.torproject.org !people.torproject.org
  ProxyJump people.torproject.org

Or with old ssh versions (before OpenSSH 7.3, or Debian 10 "buster"):

Host *.torproject.org !people.torproject.org
  ProxyCommand ssh -l %r -W %h:%p people.torproject.org

If your local username is different from your TPO username, also set it in your .ssh/config:

Host *.torproject.org
  User USERNAME

It is also worth keeping the known_hosts file in sync to avoid server authentication warnings. The server's public keys are also available in DNS. So add this to your .ssh/config:

Host *.torproject.org
  UserKnownHostsFile ~/.ssh/known_hosts.torproject.org
  VerifyHostKeyDNS ask

And keep the ~/.ssh/known_hosts.torproject.org file up to date by regularly pulling it from a TPO host, so that new hosts are automatically added, for example:

rsync -ctvLP perdulce.torproject.org:/etc/ssh/ssh_known_hosts ~/.ssh/known_hosts.torproject.org