[ILUG] Network / DNS Problems

[Niall Richard Murphy]

On Wed, Nov 21, 2001 at 10:20:03AM -0000, Lemon, Matthew wrote:

Hi Matt,

One point to note is that nslookup is not the best debugging tool
for situations like this. Why?

Nslookup does a PTR query on the server's IP address (so as
to tell you its name). It sends this PTR query to the server 
you specify on the command line, and chokes if this PTR
lookup fails. So if you don't have the reverse defined you
can get spurious errors which don't help figuring out what's 
going on. (In particular "Can't find server name for address
172.16.100.1" is suggestive.)

Niall
 
> I installed RH 7 onto my desktop machine without a problem.  BUT when I try
> to ping an internal network address by name it fails.  I can ping it by IP
> address OK though.  The installation is configured with two DNS addresses
> and when I put an external web address into my browser it finds it by name.
> So it appears that the DNS for external addresses is working and the
> internal DNS isn't.
> 
> How can this be ?  I can ping the internal DNS so I know that it can see it,
> if I do an NSlookup then I get a message that says :
> 
> 	***Can't find server name for address 172.16.100.1: No response from
> server
> 	Default Server: ns.isi.ie
> 	Address 192.111.39.1
> 
> Any ideas ?
> 
> Thanks,
> 
> Matt 
> 
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