Vip is always up even if the servers behind service port are down

No. You will have to use an extended monitor. Example, HTTP, or full TCP monitor that sends some data and looks for something in the output returned by the server.

A standard VIP will only terminate a connection after it receives data, and then does not find a pool member to send it to.

Alternatively, a Performance-L4 VIP will fail on the first SYN if there is no pool member, but you lose all the layer 7 capabilities of a standard VIP.