nslookup-non existent host/domain

[Barry Margolin]

In article <4.3.2.20000322090032.00b36100 at dvs.nuphase.com>,
Maria Teresa Pineda  <mariap at digitalvideosystems.net> wrote:
>Hi, I hope somebody can help me. I can not get answer for some external 
>domains and for anothers ones I do. For example if I try with psi.com I get 
>"non existent host/domain" , if I change for another server (like 
>a.root-servers.net) I get answer. If I try, with my server, the external 
>domain ibm.net (for example) I get answer. Also I realize that if I ask for 
>psi.com using nslookup with q=any I get answer, the same happen with 
>q=ns  but with q=a I do not get answer ("non existent host/domain"). If I 

Often the domain doesn't have an address of its own.  Since it's just used
for mail, it will only have NS, SOA, and MX records.  nslookup has a bug:
it says "nonexistent host/domain" even though it means "the name exists, it
just doesn't have any records of the type you requested".  That's why you
should use dig rather than nslookup -- you can tell the difference by
whether it says "status: NOERROR" or "status: NXDOMAIN" (the latter means
that the name doesn't exist at all).

>try "dig -x 38.8.5.2" (which is one of psi.com's name server) I get answer, 
>but if I try ping 38.8.5.2  I get " ICMP net unreachable".
>The same problem happen with akamaitech.net , exenet.com , shellwilcox.com 
>domains.

Make sure your Internet router has "ip classless" configured on it.  If
not, you may have trouble communicating with external addresses that begin
with 38.

-- 
Barry Margolin, barmar at bbnplanet.com
GTE Internetworking, Powered by BBN, Burlington, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
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