NSLookup vs. Ping results

  • Thread starter Thread starter D0Thomas
  • Start date Start date
D

D0Thomas

What would cause the Ping command to not resolve an address (such as
www.yahoo.com) when the NSLookup utility can resolve the address just fine?

I have a win2000 client that can ping the IP address directly
(68.142.197.80) but when I ping www.yahoo.com it says host not found. Yet,
typing NSLOOKUP www.yahoo.com resolves the addresses ok.

TIA
 
D0Thomas said:
What would cause the Ping command to not resolve an address (such as
www.yahoo.com) when the NSLookup utility can resolve the address just fine?

I have a win2000 client that can ping the IP address directly
(68.142.197.80) but when I ping www.yahoo.com it says host not found. Yet,
typing NSLOOKUP www.yahoo.com resolves the addresses ok.
Click to expand...

Most likely reason is client side cache is wrong, but a
negative cache entry is only 5 minutes so that would imply
it didn't last long or that you actually had a wrong (but
actual) answer in the cache.

If you eliminate the client side cache it might be due to
the nslookup using a different set of DNS servers (e.g.,
internal vs. external) than the ping (client computer)
resolver.

This comes from mistakenly trying to us two 'sets' of
DNS servers on the client NICs.

Internal Clients MUST use strictly the internal DNS
servers -- and these internal DNS server must be
responsible for resolving/forwarding any external name
requests.
 
D0Thomas said:
What would cause the Ping command to not resolve an address (such as
www.yahoo.com) when the NSLookup utility can resolve the address just
fine?
I have a win2000 client that can ping the IP address directly
(68.142.197.80) but when I ping www.yahoo.com it says host not found.
Yet, typing NSLOOKUP www.yahoo.com resolves the addresses ok.

TIA
Click to expand...

In addition to Herb's post, the nslookup command has it's own resolver
service, but the ping command uses the system's resolver service, which can
include other factors, such as what Herb mentioned about what DNS servers
are listed, the client side cache, which gets populated from what's in the
hosts file and previous queries.

Plus nslooku is a strict DNS query over UDP 53. Ping relies on the system to
query it.

Are you having any problems with resolving other names?

--
Regards,
Ace

Please direct all replies ONLY to the Microsoft public newsgroups
so all can benefit.

This posting is provided "AS-IS" with no warranties or guarantees
and confers no rights.

Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft Windows MVP - Windows Server - Directory Services

Paramount: What's up with taking Enterprise off the air??
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