A top local-to-jump-to-target route keeps target authentication local; a lower remote socket exchanges requests and signatures with the local agent.

Forwarding an SSH agent

Agent forwarding is not the agent itself. A local agent can answer authentication requests without sending the private key to the server. Forwarding additionally makes that service reachable through a socket on a remote host. Keeping key material local therefore does not mean keeping its authentication capability local. ...

February 9, 2028 · 4 min · XB Field Notes