A problem with the GSLB.

We have two sites, Site A and Site B. In both locations we have two pairs of Netscalers with the same firmware version (NS12.1 55.18). On Netscalers we have some partitions and the GSLB has been configured in particular on the Partition A partition. The GSLB itself works correctly (I am currently testing it only on a virtual server with a fictitious domain example.com). If I launch the GSLB Auto Synchronization from the GUI everything is fine. Any changes I make on one of the two GSLB sites are correctly reflected on the other. I come to the point: both on Site B and Site A Netscaler the authoritative DNS for the *.example.com zone (10.194.79.13 for Site B and 10.194.79.53 for Site A) are configured as virtual servers. However, it happens that if you try to nslookup exmple.com by querying 10.194.79.13 , no answer is obtained, while querying 10.194.79.53 correctly obtains the two IPs of the GSLB services: 10.156.146.58 and 10.156.146.59. Before upgrading from NS12.1 51.16.nc to NS12.1 55.18, I remember perfectly well.

Problem Cause

This was a configuration problem.  We are not sure if this config existing before.