Can GTM redirect DNS requests to external host?

My GTM isn't working properly in that the load is not distributed to the two LTMs it's controlling based on the load balance method I chose. In fact, one of the LTM does not get any request from the GTM. Using tcpdump I can observe heavy traffic between the GTM and one of the two LTMs.

 

 

I have an additional GTM sychronized with the "Primary" GTM. Before I have this additional/redundant GTM joined the synchronization group, the primary GTM was able to do load balance between the two LTMs using method such as Round Robin. However, after the new GTM joined the group, the system is not working anymore.

 

 

How do I take a GTM out of the synchronization group? And if I do need the redundant GTM, how do i do that? I followed Chapter 6 in BIG-IP GTM and Link Controller: Implementations.

 

 

Thanks,

 

-Xi