yenjet (
Thu, 22 Apr 1999 09:10:23 +0800 (GMT)

What I suspect is you have wrong delegation from you ISP.

OK, below are the steps you could folllow to trouble shoot the problem:

First of all, do a nslookup from outside on other IP address. If the
nslookup also fail for other (old) IP address, then the answer is obvious
that you don't actually have the correct reverse doamain delegation. This
is what the O'Reilly book means PTR is not setup right.

You can perform the following steps to check whether you have the correct
delegation or not:

Take for example, you have the one class C address been delegated to you
for 202.101.20.x and you up stream ISP's name server is,

$ nslookup -q=any

Check the nameserver whether is pointing to your existing DNS server or not.
If not, means you don't have the correct delegation (or meaning you don't
have right to create any entry). If the nameserver for the is pointing to your up stream ISP namer server,
then maybe you coulod ask you ISP to delegate it to you.

This is common error for system administrator to setup a name server.
They usually forget to get the delegation from their ISP.

For the reverse domain, you don't have to get
delegation from ISP, it's automatic belongs to you.

Yes, one more thing, if you everything seems OK to you and you still
connot find what's the problem, then you might consider not to use
nslookup, use dig instead. I also encounter problem sometimes when I use
nslookup but not dig.

Good luck.

On Wed, 21 Apr 1999, intalt wrote:

> An nslookup to both the new ip and the new hostname work from
> our network, and a nslookup to the new name from outside our network
> works fine, but an nslookup to the new ip from outside returns non-existent
> host/domain. What else do I have to change to get the outside to be able to
> do gethostbyaddress correctly? I've looked in the O'Reilly "DNS and BIND"
> book but the only thing it mentions for this problem is that the PTR isn't
> set up
> right, but it is setup just like the rest of the hosts, all of which work
> fine. Anyone
> have any ideas?


== Yen Jet ==

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Chan: "The bad news is, the Y2K bug will make all of our computers
thinks it's the year 1900. The good news is, that gives us
an extra 100 years to fix the problem!"

Chan: Let's do => lynx http://3401483384/


To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to