Configuring Multiple Spanning Tree Protocol

Use the following procedure to configure the Multiple Spanning Tree Protocol.

Procedure

Enter Global Configuration mode:

enable

configure terminal
Configure MSTP:

spanning-tree mstp

Example

Configure Multiple Spanning Tree Protocol to configure the MSTP configuration version.

Switch:1(config)# spanning-tree mstp forward-time 500 max-age 3000 max-hop 200 pathcost-type bits32 priority 8192 tx-holdcount 10 version mstp

Variable Definitions

Use the data in the following table to use the spanning-tree mstp command.


Variable	Value
forward-time <400-3000>	Configures the MSTP forward delay for the bridge from 400 to 3000 hundredths of a second.
max-age <600-4000>	Assigns the MSTP maximum age time for the bridge from 600 to 4000 one hundredths of a second.
max-hop <100-4000>	Assigns the MSTP bridge maximum hop count. The range is 100 to 4000 one hundredths of a second. The original MIB erroneously designated the value in hundredths of a second, when it should have been in hops. The replacement MIB kept the range at 100-4000 to remain backwards compatible. To convert this value to hops, divide by 100 so 100-4000 equals 1-40 hops.
msti <1-63> priority <0–65535>	Assigns the MSTP MSTI instance parameter.
pathcost-type {bits16\|bits32}	Assigns the MSTP default pathcost type to either 16 bits or 32 bits. The default is 32 bits.
priority <0-61440>	Assigns the MSTP bridge priority in a range of 0 to 61440 in steps of 4096.
region [config-id-sel <0-255>] [region-name <WORD 1-32>] [region-version <0-65535>]	Assigns the MSTP region commands: config-id-sel—Assigns the MSTP region configuration ID number. The range is 0 to 255. region-name—Assigns the MSTP region name. The character string can be a range of 1 to 32 characters region-version—Assigns the MSTP region version. The range is 0 to 65535.
tx-holdcount <1-10>	Assigns the MSTP transmit hold count. The range is 1 to 10.The default value is 3.
version {mstp\|rstp\|stp-compatible}	Assigns the bridge version. Although STP and MSTP are variations of the same spanning tree protocol, they communicate information differently. A switch in MSTI mode cannot recognize the spanning tree groups running on a chassis configured with STP. MSTP spanning tree groups are not the same as STP spanning tree groups. Using a switch in MSTP mode with another chassis in STP mode can create a loop in the network. You must configure protocol migration to true on all spanning-tree enabled interfaces when you change the spanning tree version from STP-compatible to MSTP for those interfaces to work in the proper mode. Note: You cannot configure the MSTP version when MSTP-Fabric Connect Multi Homing is enabled on the switch.