dns resolution on hpux

[Shivkumar]

Dear Sirs;

I am doing nslookup for a particular server say jasmine. When i do nslookup from some other server in the same network i get the response from a dns server for this server (i mean its resolution is taking place from a dns server successfully). It returns the name of the dns resolver as well as its own name and ip.

But when did nslookup for server jasmine from the same jasmine server i got the below response:

# nslookup xx.xx.xx.xx
*** Can't find server name for address xx.xx.xx.xx: Non-existent domain
Using /etc/hosts on: jasmine

looking up FILES
Trying DNS
Name: jasmine.abc.com
Address: ip address

How do i find out that this server has been configured with a dns server for its name resolution ?

Thanks,
Shiv

[Hakan Aribas]

In Sam
1. Networking and Communication
2. DNS (Bind)
3. Actions --> Specify name server

You can write your Windows DNS server or any valid DNS server

[Raj D.]

Hi Shiv,

You can check /etc/resolv.conf configured properly.

nameserver entry must be there..
cat /etc/resolv.conf

domain domain.com
nameserver www.xxx.yyy.zzz
nameserver www.xxx.yyy.zzz

Cheers,
Raj.

[Raj D.]

where www.xxx.yyy.zzz your name server(dns) IP address. And you must be able to ping that..

Cheers,
Raj.

[Raj D.]

Shiv,

Also check your gateway and routing configuration:

# netstat -rn
# cat /etc/rc.config.d/netconf

Cheers,
Raj.

[Bill Hassell · Accepted solution]

There are two parts to name resolution. First is the /etc/nsswitch.conf file. The man [age is: man switch

What this file does is to specify the first step, then optional sec ond and third steps in resolving a name. The line in /etc/nsswitch.conf is: hosts

Now if there is no nsswitch.conf, then resolv.conf specifies the domain name for this server and the one (or up to three) DNS server to use. If resolv.conf does not exist, then only /etc/hosts is used.

Now if the above nslookup there are several parts:

> nslookup xx.xx.xx.xx
> *** Can't find server name for address xx.xx.xx.xx: Non-existent domain

This line is the first test nslookup makes--to validate the first DNS server by asking the server if it knows it's own IP address. In your case, the DNS server is misconfigured because it doesn't know it's own name. This is just a warning but take it to your DNS admins.

> looking up FILES

The nsswitch.conf than asks the resolver to search /etc/hosts. This is a good setting since you can immediately fix DNS oversights by putting the fix in your own hosts file.

> Trying DNS

Now your server asks thr DNS server and gets the result. The difference between other HP-UX server is in /etc/nsswitch.conf, and similar resolver rules in other Unix flavors.

You can always test a specific DNS server by telling nslokup what server to use:

nslookup xx.xx.xx.xx dd.dd.dd.dd

where dd.dd.dd.dd i the IP address of a specific DNS server. Note that nslookup has been patched a lot over the years and may look different depending on the version.

[Mahesh Kumar Malik]

Hi Shiv

1. Check that server "jasmine" has entry in DNS server.

2. nsswitch.conf file points to look for dns [NOTFOUND=return UNAVAIL=continue TRYAGAIN=return]

Regards
Mahesh

[Muthukumar_5]

Resolvation is based upon /etc/nsswitch.conf hosts: setting.

If you setup as,

hosts: dns files

control will go to /etc/resolv.conf file. You have to setup domain: domainname.ext and nameserver: settings correctly.

It is good to keep files and then dns.

hosts: files dns

-- /etc/hosts --

xx.xx.xx.xx host.domain.com host

If you use nslookup or nsquery it will resolve with fqdn now.

hth.

[Yogeeraj_1]

hi,

I have learnt a lot from the well-detailed documentations found at:
http://docs.hp.com/en/B2355-90685/index.html

or download the full e-book from:
http://docs.hp.com/en/B2355-90685/B2355-90685.pdf

hope this helps too!
kind regards
yogeeraj