known_hosts and multiple hosts through a NAT router

[Daniel Kopetzky]

The .ssh/known_hosts table cannot handle reaching different sshd
servers behind a NAT router. The machines are selected by having
the SSHDs respond to differnt ports.

A second request would be to allow known_hosts checking solely on
the dns name, wildcarding the IP address. This would be useful
to avoid continuously warning the user every time you connect
to a machine with a changing IP address (e.g. dynamic-ip DSL home machine).
Without that you can fall for DNS typo squatters (e.g my
fingers found     ****.hoemip.net  rather than homeip.net and
I didn't even notice because I was used to the noise warning
that a laptop's IP address had changed.