memory core dump on nslookup name server

[Franky Leeuwerck_2]

Hello everyone,

I receive complaints from users that their C/S applications running on an HP-UX DBMS server are slow in general.

When running on the DBMS server an nslookup on the DNS's ip-address I get this message :

nslookup 999.999.999.999
*** Can't find server name for address 999.999.999.999: Non-existent domain
Using /etc/hosts on: hostname

looking up FILES
Trying DNS
Trying NIS
Memory fault(coredump)

However, running an nslookup on another ip-address gives a nice answer.

Both DNS and DBMS server are running in a remote site. I have only access to the DBMS server. I assume that the DNS is still running, but I can't verify it.

If the assumption that the DNS is running, how can I check if the DNS resolving on the DBMS server is working fine ?

Thanks in advance,

Franky Leeuwerck

[Suresh Patoria]

Hi,

u trying to nslookup 999.999.999.999

It is not correct IP address

check ur DNS server IP Address then u try

Thanx

[Mark Grant]

The first place I would look is /etc/nsswitch.conf and make sure it looks OK (assuming you really aren't using 999.999.999.999).

You can at least check your DNS server is up and running by getting the name/address of the DNS server from /etc/resolv.conf and pinging it.

[Franky Leeuwerck_2]

Suresh Patoria,

I did the test with the correct ip-address.

I used the format 999.999.999.999 just for masking the ip-address of this (Windows) host.

Maybe I should have used xxx.xxx.xxx.xxx .

Any more idea's ?

Franky

[Franky Leeuwerck_2]

Mark,

I see it's a bit confusing with the 999.999.999.999. Let's forget about this and use the real numbers.

The nsswitch.conf looks like :
hosts: files[NOTFOUND=continue UNAVAIL=continue] dns [NOTFOUND=continue UNAVAIL=
continue TRYAGAIN=return] nis
protocols: nis [NOTFOUND=continue UNAVAIL=continue] files
services: nis [NOTFOUND=continue UNAVAIL=continue] files

This is the contents of /etc/resolv.conf :
search rome.bekaert.com bekaert.com dcz.bekaert.com dyersburg.bekaert.com rogers
.bekaert.com
nameserver 193.74.171.191 # scusro01
nameserver 195.207.194.133 # grd01s02
nameserver 193.74.166.99 # zenana

nslookup 193.74.171.191
*** Can't find server name for address 193.74.171.191: Non-existent domain
Using /etc/hosts on: jupiter1

looking up FILES
Trying DNS
Trying NIS
Memory fault(coredump)

ping 193.74.171.191
PING 193.74.171.191: 64 byte packets
64 bytes from 193.74.171.191: icmp_seq=0. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=1. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=2. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=3. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=4. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=5. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=6. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=7. time=0. ms
64 bytes from 193.74.171.191: icmp_seq=8. time=0. ms

----193.74.171.191 PING Statistics----
9 packets transmitted, 9 packets received, 0% packet loss


Running a ping on the ip-address of the DNS succeeds, so the machine that is supposed to be the DNS is up and running.

Franky

[Sanjay Kumar Suri]

I have following observation:

hosts: files[NOTFOUND=continue UNAVAIL=continue] dns [NOTFOUND=continue UNAVAIL=continue TRYAGAIN=return] nis

You want to check /etc/hosts first?

Try
#nslookup
>set swtrace
>System_name

sks

[Franky Leeuwerck_2]

Hi Sanjay,

It looks like my DBMS host is not using its primary DNS server :

jupiter1: nslookup
*** Can't find server name for address 193.74.171.191: Non-existent domain
Using /etc/hosts on: jupiter1

> set swtrace
> scusro01
Using /etc/hosts on: jupiter1

lookup source is FILES
Using /etc/hosts on: jupiter1

looking up FILES
*** No address information is available for "scusro01"

Switching to next source in the policy
lookup source is DNS
Name Server: grd01s02.dcz.bekaert.com
Address: 195.207.194.133

Trying DNS
Non-authoritative answer:
Name: scusro01.rome.bekaert.com
Address: 193.74.171.191

> exit

[Sanjay Kumar Suri]

Try another thing:

Reverse the order of name servers from:
nameserver 193.74.171.191 # scusro01
nameserver 195.207.194.133 # grd01s02
nameserver 193.74.166.99 # zenana

to
nameserver 193.74.166.99 # zenana
nameserver 195.207.194.133 # grd01s02
nameserver 193.74.171.191 # scusro01

and check again.

sks

[Franky Leeuwerck_2]

Hi Sanjay,

I changed the order in resolv.conf.

jupiter1: cat resolv.conf
search rome.bekaert.com dcz.bekaert.com dyersburg.bekaert.com rogers.bekaert.com

nameserver 195.207.194.133 # grd01s02
nameserver 193.74.171.191 # scusro01
nameserver 193.74.166.99 # zenana

> 193.74.171.191
Using /etc/hosts on: jupiter1

lookup source is FILES
Using /etc/hosts on: jupiter1

looking up FILES
*** No hostname information is available for "193.74.171.191"

Switching to next source in the policy
lookup source is DNS
Name Server: grd01s02.dcz.bekaert.com
Address: 195.207.194.133

Trying DNS
*** grd01s02.dcz.bekaert.com can't find 193.74.171.191: Non-existent domain


This time the 'first' DNS server is used.

Franky

[Franky Leeuwerck_2]

After switching the primary and secondary DNS server in the resolv.conf file, I don't get a memory core dump anymore.

This leaves me to the next question :
is everything configured in the correct way for using this DNS server ?

This are the current settings :
jupiter1: cat resolv.conf
search rome.bekaert.com dcz.bekaert.com dyersburg.bekaert.com rogers.bekaert.com

nameserver 195.207.194.133 # grd01s02
nameserver 193.74.171.191 # scusro01
nameserver 193.74.166.99 # zenana
jupiter1: cat nsswitch.conf
hosts: files [NOTFOUND=continue UNAVAIL=continue TRYAGAIN=continue SUCCESS=retur
n] dns

I would like to have scusro01 as primary DNS server. So, assuming this DNS host is up and running, are there any additional settings necessary ?

Franky

[Sanjay Kumar Suri]

Can you check you
.rhosts
/etc/hosts.equiv
/var/adm/inetd.sec
~/.netrc
files as well?

Fully qualify each of the hostnames they contain.

sks

[TommyT]

Hi.
Have you tried to set domain in resolv.conf
like:
domain bekaert.com
nameserver 193.74.171.191 # scusro01
nameserver 195.207.194.133 # grd01s02
nameserver 193.74.166.99 # zenana

//Tommy

[Franky Leeuwerck_2]

Thanks all for your replies.

In the meantime, the problem still exists.
Apparently the Windows DNS server in the LAN does not solve DNS requests for the Unix box.

The local IT man is looking further into this.

Regards,
Franky