Alternative GTM redundancy configuration

Hi,

 

 

I'm helping coworkers with a new GTM rollout, but have no experience outside of concepts and some understanding of LTM mechanics. I have a question about a proposed method for handling GTM redundancy in a non-standard way.

 

 

Background

 

 

Site A

 

 

=LTM cluster (pair of 6400s), public IP space (behind edge firewall)

 

=single GTM (one 1600), public/private IP space (behind DMZ firewall)

 

 

Site B

 

 

=LTM cluster (pair of 6400s), public IP space (behind edge firewall)

 

=single GTM (one 1600), public/private IP space (behind DMZ firewall)

 

 

The plan currently is to use the GTM's only for DNS, both external and internal clients. Since we only have 1 GTM per site, we want to setup 2 LTM VIPs at each site for the public NS records and then populate the VIP pools with the 2 GTMs, one at Site A and one at Site B. This is being done instead of using the built-in failover magic on the GTMs which requires a pair at each location.

 

 

First of all, has anyone done this successfully? what gotchas did you find?

 

 

Secondly, what might we be losing in terms of GTM DNS capabilities with this sort of arrangement?

 

 

Thanks in advance,

 

 

--rc