GTM - Static Persist

In that case, you could use an iRule to insert a "Data Center Affinity" cookie for each new user that comes in. The same iRule would check for the existence of the cookie - if it matches the DC that the user has come to, all is well, continue. If, however, the user shows up at DC-"A" with a cookie inserted for DC-"B", you could issue a redirect to the other VIP. If you have layer 2 connectivity between Data Centers, you could also accept the user at DC-A, but then route the request to a node member at DC-B. Or perhaps proxy the request.

 

 

There are a couple of different ways to skin this issue - DC affinity is a big deal for exactly the situation you've outlined. A change in a users's LDNS could have them at Site B when they began their session at Site A, which possibly Breaks Things in an Undesirable Way.