Agent Forwarding
Agent forwarding is a special case of remote tunneling. In agent
forwarding, Secure Shell connections and public-key authentication data
are forwarded from one server to another without the user having to
authenticate separately for each server. Authentication data does not
have to be stored on any other machine than the local machine, and
authentication passphrases or private keys never go over the
network.
For more information, see Appendix ssh-agent2 and ssh-add2.
