nslookup returns PTR, dig doesn't

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Level 4

1,101 points

nslookup returns PTR, dig doesn't

Hi all

Mac OS X Server 10.3.3 - 9 (yes, I checked several different versions...)

I have a problem with Network Utility.app - please let me know if I am alone with this or not.
If I choose "use 'dig' in place of 'nslookup'", and enter an IP address I get nothing in return. it works when I leave this setting alone.

dig -x IP returns what it should. lookupd -d - then HostWithInternetAddress: IP, too - so I think I don't need to worry. Please correct me if I am wrong.

Regards

Greg

Posted on Oct 18, 2005 2:31 PM

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Answer 1

UptimeJeff

Level 4

3,479 points

Oct 18, 2005 5:46 PM in response to madconqueror

Dig, by default, doestn't look-up PTR records where nslookup will.

Simple enough... In Network Utility you can select the type of record to look-up when using Dig or NSLookup.
There is a pop-up in the Network Utility where you can select the record type. If you use Dig, then select 'Host Name for Address" in this pop-up if you want a reverse (PTR) record.

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Answer 2

madconqueror Author

Level 4

1,101 points

Oct 18, 2005 5:54 PM in response to UptimeJeff

Doesn't work:
connection timed out; no servers could be reached.

dig -x 192.168.20.11
gives the correct answer without delay

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Answer 3

UptimeJeff

Level 4

3,479 points

Oct 18, 2005 6:27 PM in response to madconqueror

That's a private IP address.
The only way you'll get a response is if you're running your own DNS server and have a zone file for that zone (reverse).

You didn't mention if you were running your own name server.

Jeff

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Answer 4

madconqueror Author

Level 4

1,101 points

Oct 18, 2005 6:33 PM in response to UptimeJeff

Sorry about this one, yes I do have a DNS server running, no connection to WWW... but even then - strange behaviour isn't it?

I mean, in Terminal, dig, nslookup, lookupd -d - all respond immediately to A and PTR requests and give correct answers. But in Network Utility.app, dig is not answering PTR requests, but A's okay. nslookup in Network Utility.app is fine both ways.

Ever seen something like this?

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Answer 5

UptimeJeff

Level 4

3,479 points

Oct 18, 2005 6:47 PM in response to madconqueror

It's working, so I wouldn't sweat it.
Network Utility is just a front end. All that matters is the back end.

On the 10.3.9 server I checked.....
If I use Network Utility to Dig an IP address and leave the record type default, I get no answer. This is exactly the same as when I do the same from command line without options "dig 192.168.1.1".
In Network Utility, if I use NSLookup, I can lookup a reverse record and it answers correctly. Same results as when I do this from command-line "nslookup 192.168.1.1"

So it seems consistent.

Jeff

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Answer 6

madconqueror Author

Level 4

1,101 points

Oct 18, 2005 6:55 PM in response to madconqueror

Some more info/thoughts on my side:

The only thing I did was to create a new zone and then add A and PTR records for the server itself. I guess it could have something to do with /etc/resolv.conf and a missing listen-on in /etc/named.conf.
I hope this only affects the GUI, otherwise, I really don't know what I could have done wrong here (I tried this several times, with different configuration files - well I have no "known-good" ones...)
I could imagine that the GUI does something along the lines of
dig @192.168.20.11 -x 192.168.20.11

I mean, it sounds almost reasonable that a DNS server doesn't answer itself who it is, but answers
dig -x 192.168.20.11
dig testsrvr.myzone.int
correctly, because this could be sent over the loop-back address

I'll test this tomorrow.

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Answer 7

madconqueror Author

Level 4

1,101 points

Oct 18, 2005 6:57 PM in response to UptimeJeff

Thank you for verifying this! I appreciate this very much.

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