DNS Persistence in GTM

You will do both at the same time. You'll create two pools for the wideip. You'll use topology based routing to select which pool. Within each pool you'll do global availability. The global availability would select between the DC1 and DC2 IP address(es). In this flow... we'll assume the request came from Range1 and should select Pool1 which points to DC1 ( or DC2 if DC1 is down ) Range1 Request to GTM -> Based off topology select Pool1 -> Based on Global Availability Pool1 always returns the DC1 IP address ( Pool1 will return the DC2 IP address ONLY if the DC1 IP address shows down from some monitor ).