ssh-proxycommand very slow to respond when host is not resolvable
nc and socat take a very long time to respond/return when the host is not resolvable. This is a big problem for the ssh-proxycommand, since it exec's nc/socat to make the tcp connection to the host, and if the host is not resolvable the proxycommand just hangs until nc/socat return, which can take many minutes. Should we do some sort of check on the resolvability of the host before exec'ing nc/socat?
(from redmine: created on 2009-07-22, closed on 2009-12-21, relates #1141 (closed))