topic Re: name resolution issue in Operating System - HP-UX

name resolution issue

kholikt — Tue, 11 Jun 2002 00:38:12 GMT

I have a very funny problem. I have one hpux host, that it cannot resolve it's own name

# hostname
tadb
# nslookup
Using /etc/hosts on: tadb

> tadb
Using /etc/hosts on: tadb

looking up FILES
Name: tadb.com
Address: 172.16.15.80
Aliases: tadb

> tadb.com
Using /etc/hosts on: tadb

looking up FILES
Trying DNS
*** dns01.com can't find tadb.esc: Non-existent domain
>

But my nsswitch.conf and seems to be fine.
# cat /etc/nsswitch.conf
hosts: files [NOTFOUND=continue UNAVAIL=return] dns [NOTFOUND=return UNAVAIL=return TRYAGAIN=return]

171.16.15.84 tadb.esc tadb

Re: name resolution issue

Scott Van Kalken — Tue, 11 Jun 2002 00:40:18 GMT

try setting the UNAVAIL to continue in nsswitch.conf as well.

This will let you know if it finds it but thinks it's unavailable.

Re: name resolution issue

MANOJ SRIVASTAVA — Tue, 11 Jun 2002 02:35:50 GMT

Hi Kholikt

The issue can be

1. Improper resolv.conf , ie does it point to the coreect nameserver .

2. DNS entry itself in the naeserver being pointed by resolv.conf.

Try this , jsut rename the resolv.conf to abc.conf
and try to do a nslookup , if the server checks for /etc/hosts and resolvs it corectly then please do aping to the neamserver and then try checking hte enteries there in.

Manoj Srivastava

Re: name resolution issue

T G Manikandan — Tue, 11 Jun 2002 04:00:59 GMT

First you can resolve the host by /etc/hosts file then you can go ahead with dns.

move your /etc/resolv.conf file.
take a copy of your /etc/nsswitch file
#mv /etc/resolv.conf /etc/resolv.conf.old
#cp /etc/nsswitch.conf /etc/nsswitch.conf.currentdate
#cp /etc/nsswitch.files /etc/nsswitch.conf

check whether you have entries for the localhost in your /etc/hosts file

check whether it is resolving now.If it resolves make the old changes and try making it resolve using dns.

Thanks
G Manikandan

Re: name resolution issue

Kurt Beyers. — Tue, 11 Jun 2002 04:43:53 GMT

Hi Kholikt,

I guess Omniback is involved in this story as well. See the following thread as well:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xc072107d277ad611abdb0090277a778c,00.html

Kurt

Re: name resolution issue

John Dvorchak — Wed, 12 Jun 2002 13:01:12 GMT

From what you sent us, I really can't tell the problem. It would be helpful if you included the /etc/resolv.conf file and grep tadb from /etc/hosts i.e.

>grep tadb /etc/hosts

But it looks like the system doesn't know it's FQDN (Fully Qualified Domain Name) like
tadb.your.com.

There are a couple of ways for the computer to find it's own name. I suggest putting the first entry in /etc/hosts as:
172.16.15.80 tadb.your.com tadb

and having your domain set in the resolv.conf file:

domain your.com
server 123.234.123.234 #your Nameserver address

Your /etc/nsswitch.conf file says to try /etc/hosts first then DNS second.

Re: name resolution issue

Jack Werner — Wed, 12 Jun 2002 16:09:32 GMT

See what the tadb entry in /etc/hosts looks like:
[171.16.15.84 tadb.com tadb]?

This could be different from the hostname in /etc/nsswitch.

What is the proper fully qualified DNS name of the tadb host: tadb.esc or tadb.com ?

Re: name resolution issue

Jack Werner — Wed, 12 Jun 2002 16:12:57 GMT

Sorry,
I specified the wrong IP address for tadb in my prior post. I looks to me like the tadb alias is assigned to 2 different IP addresses/hosts.

Re: name resolution issue

Brian Hackley — Thu, 13 Jun 2002 12:40:49 GMT

Hi,

Here's a TIP that might help you:

On HP-UX 11.0 and up, use nsquery instead of nslookup to look up hosts, passwd, and group entries. nsquery uses the actual gethostbyXXX getpwdXXX and getgrXXX interfaces, wheres nslookup does not.

For example:
nsquery hosts jbox
nsquery passwd hackley

# nsquery hosts jbox

Using "files [NOTFOUND=continue] dns" for the hosts policy.

Searching /etc/hosts for jbox
Hostname: jbox
Aliases:
Address: 10.10.10.204
Switch configuration: Terminates Search

# nsquery passwd hackley

Using "files" for the passwd policy.

Searching /etc/passwd for hackley
User name: hackley
User Id: 101
Group Id: 20
Gecos:
Home Directory: /home/hackley
Shell: /sbin/sh

Switch configuration: Terminates Search

Hope you find this helpful,

-> Brian Hackley