SUMMARY: DNS lookup broken

From: Jim Wright (jwright@phy.ucsf.edu)
Date: Fri Mar 03 1995 - 03:31:32 CST


I was trying to find out why nslookup would fail:

        % nslookup eecs.nwu.edu
        *** Can't find server name for address 128.218.14.2: Not implemented
        *** Can't find server name for address 128.218.27.2: Not implemented
        Server: NS.CC.Berkeley.EDU
        Address: 128.32.136.9

        Non-authoritative answer:
        Name: eecs.nwu.edu
        Address: 129.105.5.105

Thanks to Neil Rickert and Steinar Haug for coming up with the correct
answer.

It turns out that Sun is shipping an old, broken version of nslookup.
It uses an "IQUERY" or inverse query to ask the server what the server's
name is. This inverse query method is very inefficient to implement,
and recent versions of BIND have returned the "not implemented" reply.
Newer versions of nslookup use a PTR based method for asking the name
of the nameserver.

This problem is only with the nslookup program. Any other real or
imagined problems I may be having are unrelated to this. The consensus
is that nslookup is the only program to use IQUERY (at least on Unix).

Suggestions were:
* live with it
* get a newer version of nslookup
* ask our hostmaster to implement IQUERY in their server
* get bind-4.9.3-BETA17 - even if you don't run the BIND server there
  are some good user-level tools there
* use some other, better replacement for nslookup such as "host"
  (ask archie for it) or "dnsquery" (from bind-4.9.3-BETA17)

I'm just going to ignore it.

Thanks for your help:
  Simon-Bernard Drolet <droletb@CCG.RNCan.gc.ca>
  Neil Rickert <rickert@cs.niu.edu>
  rhyner@comm.mot.com (Mike Rhyner x6-2354)
  cindy@ddrsrv2.dny.rockwell.com (Cindy Yoho)
  "Michael (M.A.) Meystel" <MEYSTMA%DUVM.bitnet@UCSFVM.UCSF.EDU>
  Steinar Haug <Steinar.Haug@runit.sintef.no>

Jim Wright Keck Center for Integrative Neuroscience
jwright@phy.ucsf.edu Department of Physiology, Box 0444
voice 415-502-4874 513 Parnassus Ave, Room HSE-811
fax 415-502-4848 UCSF, San Francisco, CA 94143-0444



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