I am running a system that has a NAT firewall on it with two IP
addresses, one on the outside
internet, and one on an internal network. This is a debian stable
system.

I want to have different login criteria for the internal network
(passwords allowed) and the
external network (key based only) and different allowd user lists for
each. I conjecture that the
only way to do this is to run two instances of sshd with different
config files. Is there anything
in ssh that would prevent me from doing this? Has anyone tried this
and have any pointers
or gotcha's to look out for.

Thanks,
Stuart