MST Revision

Required information for an MST instance:

• instance name
• revision number
• mst to vlan mappings

intra region:
vlan to stpis are manually defined
undefined vlans fall into CIST (MST 0)

inter region:
details between regions are not know

MST is backwards compatible with legacy CST and PVST+
behaves like inter-region MST
CST root must be within the MST domain

migration, start from root bridge and work your way out

Config Steps:
1. define the following in MST config mode:
region name
revision number
VLAN to isntance mappings
2. Enable MST globally

Same election process as CST/PVST+

Changing BID priority, port cost, port priority - all done for the instance
eg. spanning-tree mst [instance] priority

BEST PRACTICE: 3 spanning-tree instances in MST