The IPv4 and IPv6 addresses assigned to a Rcs.is remain static for the life of the Rcs.is. Once the Rcs.is is destroyed, the addresses are released back into a pool of available addresses in the datacenter. Once back in the pool, the chances of obtaining the same address again are unlikely.

If you require a completely static IP address that you can reassign to Rcs.iss as needed, use a reserved IP address.