GTM sometimes returns a SERVFAIL error for wideips

Hi all,

 

I have a GTM deployed in version 11.6 and hotfix 5 and I found a strange behavior when I try to resolve wideips. When I do a DIG or NSLOOKUP sometimes I receive a SERVFAIL response from the listener.

 

The SERVFAIL error occurs for every wideip configured in the box, not a specific one.

 

Here is an example, the 10.10.1.1 ip is the listener on GTM

 

ERROR EXAMPLE

dig @10.10.1.1 www.test.com

 

; <<>> DiG 9.8.1-P1 <<>> @10.10.1.1 www.test.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 50520 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; WARNING: recursion requested but not available

 

;; QUESTION SECTION: ;www.test.com. IN A

 

;; Query time: 43 msec ;; SERVER: 201.131.209.25453(201.131.209.254) ;; WHEN: Thu Aug 6 09:54:19 2015 ;; MSG SIZE rcvd: 41

 

WORKING EXAMPLE

dig @10.10.1.1 www.test.com

 

; <<>> DiG 9.8.1-P1 <<>> @10.10.1.1 www.test.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 18068 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; WARNING: recursion requested but not available

 

;; QUESTION SECTION: ;awww.test.com. IN A10.10.200.1

 

;; Query time: 20 msec ;; SERVER: 201.131.209.25453(201.131.209.254) ;; WHEN: Thu Aug 6 09:57:03 2015 ;; MSG SIZE rcvd: 41

 

I also did a test with an wideip using a simple Irule to bypass all load balancing decision and the same occurs.

 

Example: wideip --> www.test2.com Irule: when DNS_REQUEST { host 172.16.20.200 }

 

Any ideas, why GTM is answering with a SERVFAIL message sometimes ??

 

Thanks in Advance

 

Alex