topic Re: DNS failures in Operating System - HP-UX

DNS failures

Jacob D Levin — Mon, 18 Mar 2002 19:16:08 GMT

Okay, also realized I've got multiple IDs here. Respond to this one if possible and not the other one.

I'm having an issue with resolving adresses on a WINNT DNS server. I keep getting the error "non-existent domain" whenever I try to do an nslookup and it then immediately falls over to the secondary DNS server. I beleive it to be an issue on the NT machine and not my UNIX box but was wondering if anyone has had the same issue and point me in the right direction.

thanks

Re: DNS failures

pap — Mon, 18 Mar 2002 20:51:51 GMT

Hi Check the order in your /etc/resolv.conf file.

The primary DNS server should be first entry then secondary....

# cat /etc/resolv.conf
Pri_dns_server
Sec_dns_server

Hope this helps.

Re: DNS failures

Jeff Schussele — Mon, 18 Mar 2002 21:16:22 GMT

Hi Jacob,

Also make sure that you have a search domain line in your /etc/resolv.conf example:

search mydomain.com

This effectively "appends" mydomain.com to any "short" hostname when it sends the request out to the nameservers as in pap's example.

nameserver1 xxx.xxx.xxx.xxx
nameserver2 xxx.xxx.xxx.xxx

Note you can have multiple domains in the search line & that may be necessary if you don't know which domain the host is in OR that one of the named nameservers is authoritative for the other domains & it's not your primary nameserver.

HTH,
Jeff

Re: DNS failures

Jeff Schussele — Mon, 18 Mar 2002 21:28:44 GMT

Oooops...

disregard the numbers after nameserver in my example - there should only be

nameserver xxx.xxx.xxx.xxx
nameserver xxx.xxx.xxx.xxx

As Piyush pointed out order is important - from top down - max of three.

Jeff

Re: DNS failures

Ron Kinner — Mon, 18 Mar 2002 21:49:06 GMT

Try a manual lookup and see what happens.

nslookup
Server: YourDNSname
Address: AddressofAbove
>att.com
...
Name:att.com
135.145.9.134

Verify that the Name and Address given for the DNS are correct.

Does it find att.com or does it choke?

If that fails try your own domain (with and without the .com). If these fail then your DNS is hurting. If it works without the .com then the DNS may think it has to add that to everything.

Also try a reverse lookup and give it a local ip address.

Ron

PS "exit" will get you out of lookup mode.

Re: DNS failures

Jacob D Levin — Mon, 18 Mar 2002 21:58:47 GMT

here is the actual error I get. I believe the issue truely lies on the NT box.

nslookup
***can't find server name for xxx.xxx.xxx.xxx: Non-existent domain
default name server: YYY.YYY.YYY
Address: yyy.yyy.yyy.yyy
>

xxx.xxx.xxx.xxx is the ip of my primary
YYY.YYY.YYY is the name of my secondary
yyy.yyy.yyy.yyy is the ip of my secondary

will not even attempt to resolve on the primary, immediately falls to the secondary.

Re: DNS failures

Sachin Patel — Mon, 18 Mar 2002 22:01:49 GMT

Hi
Can you even ping your primary's ip?

Sachin

Re: DNS failures

Jeff Schussele — Mon, 18 Mar 2002 22:06:42 GMT

Try to traceroute to the primary's IP. Sounds like you can't get to it.

What does

#netstat -rn show?
Do you have a default route?

HTH,
Jeff

Re: DNS failures

Jacob D Levin — Mon, 18 Mar 2002 22:19:19 GMT

I can ping the primary, no problem. It seems to be a name lookup failure. it can't resolve the host name of the primary server so it falls over to the secondary.

Re: DNS failures

Sachin Patel — Mon, 18 Mar 2002 22:28:31 GMT

Hi Jacob
You never says that you are doing nslookup on PC.

on command windows run
ipconfig /all and check
Connection-specific DNS Suffix: it sould be xxx.com

or
primary DNS suffix : xxx.com

Sachin

Re: DNS failures

Jeff Schussele — Mon, 18 Mar 2002 22:29:16 GMT

Starting to sound like a classic reverse lookup problem.
The NT DNS people HAVE to ensure that their DNS contains both "byhost" & "byaddr" entries.
Looking at the error again - I'm sure of it - can't resolve the hostname from the IP.

Sheesh you're having fun over there if the DNS "gurus" can't even get the DNS server entries right. ;~)

Good Luck,
Jeff

Re: DNS failures

Jacob D Levin — Mon, 18 Mar 2002 23:14:58 GMT

Well my DNS gurus on the NT side have all gone home for the day (lucky them) I'll catch up with them tomrrow about the "byhost" and "byaddr" entries. thanks everyone, I'll let you know how it turns out.

Jake

Re: DNS failures

Jeff Schussele — Tue, 19 Mar 2002 15:33:24 GMT

Jacob,

They probably have forgotten to include the server in the
db.xxx.xxx.xxx file in their config.
Where the xxx.xxx.xxx is the subnet.
This is the file that contains reverse name mapping. This file MUST contain every host in the subnet. Is frequently the "forgotten" entry on adds/updates.

HTH,
Jeff

Re: DNS failures

CHRISTSHONDA CAMPBELL — Tue, 19 Mar 2002 20:49:49 GMT

Whenever you have a DNS issue, first look at /etc/resolv.conf. See if you can ping each server in the list. If you can then see what nslookup says when you put in the IP address.
DNS follows the order in the /etc/resolv.conf. So if your first line is 192.3.4.5 then that is your primary DNS server. So check to see if that server is reachable.

Re: DNS failures

Jacob D Levin — Tue, 19 Mar 2002 21:10:00 GMT

Hi everyone,
thanks for all your help. it seems the NT folk had an issue with their host record??? They believe this will fix the isssue. I'll keep everyone posted.

Jake

Re: DNS failures

pap — Tue, 19 Mar 2002 23:24:15 GMT

Hi Jacob,
We are glad that you resolved your problem.
It will be great if you can assign points to all participants.....:)....