Licensing Requirements and Limitations for MSTP

Other network elements also need to support MSTP.

MSTP is a basic feature of a switch and is not under license control.

All models of S2720, S5700, and S6700 series switches support MSTP.

For details about software mappings, visit Hardware Query Tool and search for the desired product model.

The maximum number of MSTP instances on the device is 65.
MSTP BPDUs may be discarded in a scenario wherein there are many MSTIs and MSTP multi-process is configured. This is due to the default CIR of STP being insufficient. (The default CIR of STP is insufficient because the length of MSTP BPDUs increases as the number of MSTIs increases, and the number of outgoing MSTP BPDUs increases when MSTP multi-process is configured.) To avoid this situation, increase the CIR of STP.

If the CPCAR values are adjusted improperly, network services are affected. To adjust the CPCAR values of STP BPDUs, contact technical support personnel.
Enabling MSTP on a ring network immediately triggers spanning tree calculation. If basic configurations are not performed on switches and interfaces before MSTP is enabled, network flapping may occur upon changes to parameters such as device priority and interface priority.