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Resolving a Namseserver IP / Name

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16 years 3 weeks ago #25660 by androse
Hello,

We are a small network app provider, and run a modest Solaris Bind 9 Nameserver. The servers are in a rack at a center we lease from Bandcom.

Everything was fine till several days ago our nameserver started failing and our Surgemail daemon pretty much quit routing email. Of course, no one had touched anything on either Bind or the email daemon.

The company providing our IPs said 'their' provider was reorganizing the IPs (?) but that didn't affect us. I think it did, but don't know enough to prove it.

Evidence: If I run an nslookup, I get an unexpected, weird answer. Example here:

C:\>nslookup 67.107.190.2
Server: cns.s3woodstock.ga.atlanta.comcast.net
Address: 68.87.68.162

Name: 67.107.190.2.ptr.us.xo.net
Address: 67.107.190.2


See the 'Name:' result line - 67.107.190.2.ptr.us.xo.net
Why does it have the ...ptr.us.xo.net appended?

I would expect something like this for example:

C:\>nslookup 64.38.192.15
Server: cns.s3woodstock.ga.atlanta.comcast.net
Address: 68.87.68.162

Name: ns6.cwie.net
Address: 64.38.192.15

I don't know enough about what the guys providing my IPs should be doing, but I'm darn near certain they broke it, except I don't know enough to argue my case.

Can anyone enlighten me? Thanks!

Andy.

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16 years 1 week ago #25809 by Elohim
Because according to ARIN, XO communications owns 64.104.0.0/13 and your server's IP address sitting at 67.107.190.2 is part of this block. And this is a dynamically assigned address so the DHCP servers generated some oddball DNS for the server, i.e. 67.107.190.2.ptr.us.xo.net.

Hello,

We are a small network app provider, and run a modest Solaris Bind 9 Nameserver. The servers are in a rack at a center we lease from Bandcom.

Everything was fine till several days ago our nameserver started failing and our Surgemail daemon pretty much quit routing email. Of course, no one had touched anything on either Bind or the email daemon.

The company providing our IPs said 'their' provider was reorganizing the IPs (?) but that didn't affect us. I think it did, but don't know enough to prove it.

Evidence: If I run an nslookup, I get an unexpected, weird answer. Example here:

C:\>nslookup 67.107.190.2
Server: cns.s3woodstock.ga.atlanta.comcast.net
Address: 68.87.68.162

Name: 67.107.190.2.ptr.us.xo.net
Address: 67.107.190.2


See the 'Name:' result line - 67.107.190.2.ptr.us.xo.net
Why does it have the ...ptr.us.xo.net appended?

I would expect something like this for example:

C:\>nslookup 64.38.192.15
Server: cns.s3woodstock.ga.atlanta.comcast.net
Address: 68.87.68.162

Name: ns6.cwie.net
Address: 64.38.192.15

I don't know enough about what the guys providing my IPs should be doing, but I'm darn near certain they broke it, except I don't know enough to argue my case.

Can anyone enlighten me? Thanks!

Andy.

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16 years 1 week ago #25822 by S0lo
When I nslookup it, your desired domain shows!!:

[code:1]
nslookup 64.38.192.15

Server: Unknown
Address: 139.X.X.X

Name: ns6.cwie.net
Address: 64.38.192.15
[/code:1]

Try this, set the primary DNS on your PC to a deferent DNS server. Better be a public one or out of your company. And set nothing in the secondary DNS. Then:

[code:1]
ipconfig /flushdns
[/code:1]

Then try nslookup 64.38.192.15 again. If it works as you've wanted, Then the problem is probably a cached entry in your DNS server that will expire shortly. Not, sure though about the deep details of why it is happening.

Studying CCNP...

Ammar Muqaddas
Forum Moderator
www.firewall.cx
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