Can one set an agent timeout for a specific host?

[Chris Green]

If I set a timeout for a specific host's key does it set the timeout
for just that key/host?

I.e. if I do something like in ~/.ssh/config:-

    #
    #
    # backup, use public-key authentication
    #
    Host backup
        IdentityFile ~/.ssh/backup_id_rsa
        IdentityAgent 600

Will it just time out the key saved for backup and leave any other
keys with the default no timeout?

-- 
Chris Green