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challBOE

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Windows DNS server debug log shows linux (?) client trying to reach "PTS" and it fails

windows DNS server , 2012 r2. Roles = Active Directory Server and DNS server
Can anyone explain the following query (from DNS debug logging)

       UDP Snd 10.1.2.3    31a4 R Q [8281   DR SERVFAIL] A      (5)pts/0(0)

Where 10.1.2.3 is probably a Linux device?
My debug log is full of these. I don't know what
PTS (as a destination address) is and I dont know why its a SERVFAIL.
1. What is "PTS"
2. Why is it a SERVFAIL
3. Does this clog up my DNS server, I have a lot of these entries.
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Aard Vark
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Why is it a SERVFAIL

It means the server failed to find a valid record.

Does this clog up my DNS server, I have a lot of these entries.

No, unless your server is woefully under spec'd it won't notice. DNS servers take a lot of bogus queries every day. I can't offer any insight into why the client is sending the query though.
You might consider doing a packet capture...
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noci

PTS?   or PTR...

PTR is an attempt to get a hostname from an IP address. (aka reverse lookup).
(sometimes used for logging, or fe. authorizing a source system to mysql).

Then a gethostbyaddr() function is called, which attempts to get a hostname, if needed from a DNS server.

The system doing the query want to know the name of some other system ...
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ASKER

Nope, definitely PTS/0.
I would suggest a packet capture to show the request and response
Thanks. I am doing DNSDEBUG logs, which is similar to DIG or sniffer, which is how I discovered this.
I suspect this is a tailend of a linux client request.
I found this article, https://ns1.com/blog/decoding-dig-output, which was helpful in defining SERVFAIL versus NXDOMAIN.

I am closing this ticket, as we dont have that many Linux clients.
Thanks everyone
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noci

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Thanks everyone.