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Michael_Sproul1's avatar
Michael_Sproul1
Icon for Nimbostratus rankNimbostratus
Mar 04, 2015

GTMs in different DNS Domains

I have GTMs at two sites, which are in different DNS Domains. (e.g., A.gov and B.gov). The customer is interested in having "Global Availability" failover, in case an A Site Pool goes down, transfe...
BIG-IP DNS
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Hamish's avatar
Hamish
Icon for Cirrocumulus rankCirrocumulus
Mar 06, 2015

To make it easier on yourself, add a 3rd domain (e.g. wip.a.gov, or anything else really) and then use that for all your WIP addresses. Delegate that to BOTH GTM's. To point service at them, simply use a CNAME for the service that resolves to the WIP domain. e.g.

 

service.a.gov IN CNAME service.wip.a.gov

 

where service.ip.a.gov is the WideIP. You could then either just point all your b.gov services at the same wip.a.gov, or you could simply define a wip.b.gov as well and use that for your b.gov services).

 

You can delegate as many domains as you like to GTM, so don't sweat it.

 

Where you will have issues is if you only have a.gov or b.gov serviced by a single site... Then you'd lose the delegation for the .wip subdomain when the site disappeared... Your alternative for that is to merge the two GTM's into the same sync-domain so you can service the static NS records for the subdomains no matter which site is up/down. (And get the delegation stretched as well of course)

 

H