alex@alex:~$ ssh -A bastion.wmflabs.org
[snipped login message]
krenair@bastion1:~$ ssh nova-precise2.pmtpa.wmflabs
[snipped login message]
krenair@nova-precise2:~$ ssh -p 29418 gerrit.wikimedia.org
Permission denied (publickey).
krenair@nova-precise2:~$ exit
logout
Connection to nova-precise2.pmtpa.wmflabs closed.
krenair@bastion1:~$ ssh -A nova-precise2.pmtpa.wmflabs # THIS -A IS IMPORTANT
[snipped login message]
krenair@nova-precise2:~$ ssh -p 29418 gerrit.wikimedia.org

  ****    Welcome to Gerrit Code Review    ****

  Hi [snip], you have successfully connected over SSH.

  Unfortunately, interactive shells are disabled.
  To clone a hosted Git repository, use:

  git clone ssh://[email protected]:29418/REPOSITORY_NAME.git

Connection to gerrit.wikimedia.org closed.