RSTP is an enhancement to STP, and was designed specifically to improve spanning tree performance. Like STP, RSTP can create only one spanning tree (instance 0), and therefore cannot take VLANs into account when managing redundant paths. However, RSTP’s performance improvements generally make it preferable to STP in non-VLAN environments.
In the case where legacy RSTP bridges are on the network, BIG-IP® system
interfaces running MSTP can degrade to RSTP, just as they can degrade to STP.
Like STP, RSTP allows only one spanning tree instance on the BIG-IP system.