Whether VIP required for a standby pool

Hi,

We are having an irule which will redirect the request to standby pool if master pool is down .Below is the irule used(http profile not used) .

Question is do we need to associate a VIP to the standby pool or just pool is required and the request will get redirected .

irule:

when CLIENT_ACCEPTED {

  if { [active_members [LB::server pool ]] == 0 } {


        pool standbypool

}
}