Supose I got 1 VIP serving a serverfarm with 2 servers. Is it possible to configure the ACE in a way that if any of the servers goes down, all the requests to this serverfarm are redirected to another serverfarm?
I've tried to use backup rservers but in this case all the servers in the serverfarm had to be down for the backup server to take up.
You don't need to configure two probes. If you use the "partial serverfarm failover" technique then you can achieve waht you want. With the partial technique as serverfarm is marked as down if less than a specified percentage of the servers are available.
partial-threshold 60 back-inservice 100
policy-map type loadbalance ...
serverfarm FARM1 backup FARM2