GTM configuration for failover cluster

Hello there, Can any one tell me if my plan to configure GTM on the second device of a failover cluster will work? thank you.

 

Current situation: we have two BIGIP devices (A and B) that are located at different data center. They are configured to be in a GTM sync group and everything is working fine. We now need to install a third BIGIP at A data center (I call it A2), so A and A2 can form a failover cluster in terms of LTM/APM etc. This part is now done and fail over between A and A2 are working properly.

 

Goal: get A2 into the GTM sync group.

 

My plan: I plan to use floating IP between A and A2. So here's what I will do 1. Change A's DNS listener IP to the floating IP 2. Configure A2 to use the same floating IP as DNS listener 3. Create the necessary servers and datacenters in DNS on A2 4. force A2 to be active (A to be stand by) 5. on A2, run gtm_add (B's IP)

 

Will my plan work? Thank you.