nslookup: giving error when used with UDP

[Rich Parkin]

One obvious place to look is whether or not your Firewall/routers are
permitting UDP in the desired direction.

It's unclear which machine you're running nslookup from and what server
you're trying to query.  I'm assuming you're executing nslookup from a
workstation and the default server is a nameserver in your network. 
That nameserver must be able to receive traffic from your workstation on
port UDP 53.

It sounds to me as if something, somewhere is blocking UDP traffic. 
Either on port 53 specifically or a range of ports.  Seems a bit odd,
but possible.  Maybe your network administrator was a little too
aggressive in locking down unwanted traffic.

Richard Parkin
System Administrator
CCNA
Data Center Operations
LDMI Telecommunications

>>> Barry Finkel <b19141 at achilles.ctd.anl.gov> 4/28/2004 10:42:18 AM
>>>
=?iso-8859-1?q?sekhar=20n?= <sekhar_nv at yahoo.co.in> wrote:

>i am facing the problem with DNS/BIND.
> 
>when I tried nslookup (from the machine with Tru64 Unix OS) without
any option (meaning it uses UDP to send 
>the packets), the server is returning the error.
>nslookup hostname
>can't find hostname: Server failed
> 
>When I used nslookup -vc option(if you mention -vc option, then it
uses 
>TCP to send packets), the server is responding properly.
> 
>nslookup -vc hostname
>This time it is giving the IP address of the hostname by using the
default server.
> 
>Any help is appreciated.

"Our crystal balls are out of energy, so we cannot help you."  You can
recharge our crystal balls by giving us some more information - real
nodenames - so that we can do some remote debugging.
----------------------------------------------------------------------
Barry S. Finkel
Computing and Instrumentation Solutions Division
Argonne National Laboratory          Phone:    +1 (630) 252-7277
9700 South Cass Avenue               Facsimile:+1 (630) 252-4601
Building 222, Room D209              Internet: BSFinkel at anl.gov 
Argonne, IL   60439-4828             IBMMAIL:  I1004994