resolver mystery

[Peter Brimacombe]

on an SGI box
nslookup asp_st2 gives
216.217.92.178, 64.246.28.77, 216.40.251.1

these addresses are on the internet somewhere but they don't relate to anything I am doing

on the SGI box,
/etc/resolve.conf points to my dns running on HP-UX

but on the HP-UX box
nslookup asp_st2 just gives not found which is the answer I expect!

Can anyone explain why I am getting these bizarre addresses?

[Jean-Louis Phelix · Accepted solution]

Hi,

I don't know SGI, but on hp-ux, if a host can't be found using DNS, then it can search in files or using NIS. This feature is implemented using /etc/nsswithc.conf. Perhaps your SGI does the same and find asp_st2 in /etc/hosts file or using NIS ...

Regards.

Check nslookup policy using :

/.root # nslookup
> policy
#Lookups = 2
dns [RCCC] files [RRRR]

[Tom Jackson]

Hi:

man switch

might help.

[Shannon Petry]

It could be as the others pointed out that your actually resolving locally. nslookup will tell you where it gets it's information though. More advanced and better debugging information comes from "dig", which is a newer more advanced nslookup.

It is possible that the HP is giving the bad information, and your hp does not get the same answer because the HP is not using DNS resolver, or a differently configured /etc/nsswitch.conf.

Host information can only come from 5 places.
1. DNS
2. /etc/hosts
3. NIS
4. NIS+
5. LDAP

Lookup order is always defined by /etc/nsswitch.conf.

Chances are you are not using services 5 and 6, which limits you to 1,2, and 3.

If your using NIS, check the nis master for this entry in it's hosts table. "ypcat hosts" If it's there, remove from /etc/hosts on the nis master and rebuild maps.

Item 2 is self explanatory. Edit /etc/hosts

Item 1 is the hardest. Get a good book on DNS and have fun! ;) esp. "DNS and BIND Administration", published by O'Reilly and Associates.

Regards,
Shannon

[MANOJ SRIVASTAVA]

Also you can move /etc/resolv.conf to some other file and then check for the particualr hostname using nslookup , if it resloves using /etc/hosts then u have the answer .



Manoj Srivastava

[Peter Brimacombe]

nslookup on SGI is significantly different than HP-UX.

On the SGI, in nslookup I set debug,
then queries refer to ns1.domain777.com

also saw some reference to topclicks

still looking!