I've run into a problem with my Cisco setup and my ISP. Basically, they won't do reverse DNS on our outgoing serial interface. I currently NAT everything from internal private LAN to this serial interface. As my front end mail server is internal, that means it gets NAT'd on the way out to the serial interface. Some mail servers it talks to require reverse looksup and it fails sending mail to them.
My serial interface is xxx.xxx.190.90 and the other end of the WAN link is xxx.xxx.190.89 these are the only two IP numbers in that subnet.
My router has 3 interfaces, a serial for the WAN, and two ethernet, one for internal LAN one for a DMZ. The DMZ is xxx.xxx.168.224/240.
I'm no guru at Ciscos that's for sure, but in generaly I can figure things out if given an idea or any docs to read... is there a solution to this? Any pointers, suggested reading or whatever would be greatly appreciated.
Thanks for your help.