On Sun, 15 Sep 2002, Brook Milligan wrote:

> traceroute, http, ssh) work fine, mail delivery no longer does.
>
> I presume that this is because hosts at the receiving end of an smtp
> connection do a DNS lookup and then refuse the connection when they
> cannot find an entry for my machine.  I presume also that the correct
> solution is to obtain a public DNS entry for my machine.

Not all mail servers will refuse email because of that. But it is a good
idea to have DNS setup.

Ask the ISP (or whoever has that IP address) to make sure that it has a
hostname and an IP that reverses to it also. Most ISPs already have
generic hostnames setup.

(Or use a mailhub like another email suggested.)

> - Will obtaining a public DNS entry expose the local network to any
>   additional vulnerabilities?

No.

   Jeremy C. Reed
   http://www.reedmedia.net/