Bind vs GTM DNS

Ok. If I understand correctly, this is what I think you need:

1. Delegate a subdomain in your zone called rtr.domain.com and delegate it to your listener address of your GTM.

rtr.domain.com. IN NS gtm.domain.com.
gtm.domain.com. IN A  1.2.3.4

2. Create a CNAME record that aliases routers.domain.com to routers.rtr.domain.com.

routers.domain.com. IN CNAME routers.rtr.domain.com.

3. Create a GTM Pool that has your 100 routers in it.

4. Create a Wide-IP called routers.rtr.domain.com that contains the GTM Pool with the 100 routers.

5. Set your Linux machines up as secondary name servers of domain.com.

Now with that said, here is what you have when this is complete:

- Linux machine has a copy of the domain.com.

- Linux machine will look to itself for routers.domain.com and be sent to the alias of routers.rtr.domain.com.

- Linux machine will send request for routers.rtr.domain.com to the GTM listener address.

- GTM will process the request for routers.rtr.domain.com according to how you have configured your Wide-IP.

Let me know if this helps you out or if you need more assistance.

Chris