dns cache resolver

Hi Cory, thanks for your response. I will create an widip and delegate my domains to gtmA and gtmB that are placed on different location.when gtmA or gtmB crashed then how dns queries will be redirect to another site? this will being done by gtm ( exmp : gtmA notify to authoritative dns server about gtmB crashed and request redirecting dns queries to itself). or the authoritative dns server monitors both gtms and if one of them is fails then the server redirects queries to available gtm ?

Another question is that normally dns servers load balance queries as round robin. so if want to configure load balance method on the gtm as global availability how this will work? because the auth. dns server will load balance queries to gtms so I think the global availability method will not work.

thanks,