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Rajesh_07_16489's avatar
Rajesh_07_16489
Icon for Nimbostratus rankNimbostratus
Jan 11, 2015

What happens when clients send request to downed DC

My scenario is, we have 2 DCs with pair of LTM at each DC and single GTM is deployed for load balancing the traffic across both the DCs and we configured Round Robin at GTM end to manage both the DCs...
application delivery
BIG-IP DNS
LTM
StephanManthey's avatar
StephanManthey
Icon for Nacreous rankNacreous
Jan 11, 2015

There is an option in GTM to send multiple A-records in a sorted order upon incoming DNS requests.

 

Same mechanism is used by others for high availability. The client receives multiple answers, tries one and fails back to another after timeout.

 

Please be aware, that the sorted order of records (having a prioritization of a DC in mind) is kind of useless, as they may be re-ordered by the client´s DNS resolver or in the client.