Dynamic DNS and firewall access

[Sally Tomasevic]

Hello everyone,

I have an interesting little problem I'm hoping someone can help me out
with.  I have a few remote PCs that for which I want to provide remote
access into one of our other systems.  I've set up Dynamic DNS so that
they can do remote updates, but the local /etc/hosts.allow file still
blocks them despite the fact that I allow access to the dymamic domain.

For instance.  Say dynamic address 111.222.333.444 get updated via dynamic
DNS to be albert.dyn.mydomain.com.  My hosts.allow file has this entry.

   in.telnetd:  albert.dyn.mydomain.com

This, of course, doesn't work and is no big surprise.  The problem, as I
see it, seems to be that Linux's anti-spoofing software is rejecting this
address, or the gethostbyname() resolution happens first on the number
111.222.333.444 before it has a chance to look up the domain.  This seems
to be the likely culprit.

Questions.  Is there a way around this?  Can I create dynamic reverse
lookup files?   Any suggestions on providing a better way to allow access
to notebook clients who always connect using dymanic IP addresses?

Thanks for any and all suggestions.