Reverse DNS

[learning247]

Guys,

Here is my problem. We cannot send mail to a few domains like aol.com optonline.net etc etc. Now I know the reason is because we need to have RDNS setup. We have it setup and it seems to be working fine. But when I go to dnsstuff.com I put my public IP in the RDNS field and it cannot reslove and domain name to that ip.

Now, Our ISP is AT&T and according to them we are setup to use our own DNS Servers they don't host them we do. Which is fine and we asked them about RDNS and they said it's a problem on our end. Now how can I be 100% sure it's not us and them ? Is it still possible for them to create PTR records even though we are hosting our DNS Servers ?

Thanks
Learning247

 

[Kreichek]

The first thing you could try is whether you operate the authoritative DNS servers for the appropriate arpa domain. Assuming you want to check the authoritative name server which has the reverse zone (if your network is for example 192.168.100.0/24), type the following (">" and "#" are command prompts and should not be entered):

Using nslookup on Windows (Start-Run-nslookup)

>server ns.uni-sofia.bg
>set type=ns
>100.168.192.in-addr.arpa

Using dig on Linux

#dig -t ns 100.168.192.in-addr.arpa @ns.uni-sofia.bg

The output from this command should show your name servers which are authroritative for your 'arpa' - subdomain. The server ns.uni-sofia.bg is an open recursive name server so that you can check whether your servers are correctly listed in the DNS hierarchy. Or you can list them here, so I can check too.

---
Jordan Jordanov
Network administrator
Faculty of German Engineering Education and Industrial Management
Technical University of Sofia, Bulgaria

 

[ITPangaeaArchitect]

does your ISP point teh DNS to your router IP? Is your router configured to forward port 53 requests to an internal DNS server?

-Brandon Wilson
MCSE00/03, MCSA:Messaging00, MCSA03, A+

 

[lgarner]

Hosting DNS for your domain is one thing, hosting it for your network is another. Unless you host DNS for the IP network that you're on, AT&T will have to make the change for you. If you don't have at least a /24 address space from AT&T, you're not hosting RDNS.