Re: Name lookup question

[Jeremy Davis <jdaytona gmail com>]

Collins, Kevin [MindWorks] wrote:
> Hi,
>
> If I attempt a ping to one of those aliases, all works well - the name 
> is resolved to IP and the ping succeeds. However, if I attempt to use 
> the nslookup or host command to lookup the alias manually, it fails with 
> a SERVFAIL error.
>
> Shouldn't these commands be using the name service switch just like the 
> rest of the OS, or am I spoiled because HP-UX works the "right" way?

nslookup is sometimes modified by the reseller to do non-DNS things.

BIND and its tools, including nslookup, are often bundled with the 
operating system by the vendor. Several vendors supply versions of BIND 
and its tools that the vendor has made modifications to. These vendors 
supply their own modified versions of nslookup that "for convenience" 
bypass the DNS and use extraneous sources of information such as 
/etc/hosts and NIS.

Such modifications make nslookup unsuitable as a tool for DNS problem 
diagnosis, since one cannot determine whether a problem that (such a 
modified version of) nslookup reports is a DNS problem or a problem with 
performing lookups using one of the other sources of information.

http://homepages.tesco.net/~J.deBoynePollard/FGA/nslookup-results-different-to-ping.html