Selecting specific key from agent

[Ruediger Meier]

On Thursday 21 January 2016, William Faulk wrote:
> There are cases when a user might have multiple keys in ssh-agent,
> but wants to use a specific one. Unless I'm mistaken, this is
> currently impossible.

You can do that with option "IdentityFile", see "man ssh_config".
Either specified with -o or IMO better in ~/.ssh/config like my example 
here:

Host gcc?? gcc??? gcc*.fsffrance.org
        IdentityFile /home/rudi/.ssh/gccfarm_rudi_dsa
        IdentitiesOnly=yes
        PasswordAuthentication no

Host * !gcc?? !gcc??? !gcc*.fsffrance.org
        IdentityFile /home/rudi/.ssh/id_ecdsa

cu,
Rudi