The 03.02.08 at 21:10, Ahbaid Gaffoor wrote:
I have an AT&T Cable Modem and have regsitered a domain name against the IP address I use.
An nslookup against abc123.com gives my AT&T assigned IP, however a reverse lookup on the IP gives the AT&T name against the IP.
This seems to be a common problem. IMHO, simply your ISP has not changed their DNS, and it is an administrative/comercial problem: you'd have to contact the administrator, and have him correct it. I happens because you did not get the domain name from them, so as far as they are concerned, you domain is not abc123.com. Remember that a reverse lookup works by asking for a host name composed from the IP numbers, like 2.100.168.192.in-addr.arpa.; and the IP belongs to AT&T, so the reverse lookup asks their dns server.
From the DNS HOWTO:
5.5.1. The reverse zone isn't delegated. When you ask a service provider for a network-address range and a domain name the domain name is normally delegated as a matter of course. A delegation is the glue NS record that helps you get from one nameserver to another as explained in the dry theory section above. You read that, right? If your reverse zone doesn't work go back and read it. Now. The reverse zone also needs to be delegated. If you got the 192.168.196 net with the linux.bogus domain from your provider they need to put NS records in for your reverse zone as well as for your forward zone. If you follow the chain from in-addr.arpa and up to your net you will probably find a break in the chain, most probably at your service provider. Having found the break in the chain contact your service-provider and ask them to correct the error. -- Cheers, Carlos Robinson