Published On: August 6ᵗʰ, 2019 02:08

Cisco Enterprise Network Function Virtualization Infrastructure Software Configuration Guide, Release 3.8.1

Multiple Spanning Trees Protocol (MSTP) is introduced to the 8-port switch on ENCS 5400. MSTP enables multiple VLANs to be mapped to the same spanning tree instance, which reduces the number of spanning-tree instances needed to support a large number of VLANs.

ENCS 5400 switch supports 15 instances. Each spanning tree instance is identified by an instance ID from 1 to 15.

To enable MST:

configure terminal
switch
    spanning-tree mode mst
    commit

To configure VLAN-to-instance mapping:

configure terminal
switch
    spanning-tree mst configuration
        instance 1 vlan 15
        name mst_test
        revision 2
        commit
To configure the switch priority:

configure terminal
switch
    spanning-tree mst 1 priority 0
    commit

To configure the path cost per interface's mst instance:

configure terminal
switch
    interface gigabitEthernet 1/1
    spanning-tree mst 1 port-priority 96
    spanning-tree mst 1 cost 2
    commit

To configure the maximum hop count for all MST instances:


configure terminal
switch
    spanning-tree mst max-hops 10
    commit

Use the show switch spanning-tree mstp configuration global command to verify the MSTP configuration.


nfvis# show switch spanning-tree mstp configuration global 
spanning-tree mstp configuration global name transit-net
spanning-tree mstp configuration global revision 2
spanning-tree mstp configuration global max-hops 20

Use the show switch spanning-tree mstp configuration instance-list command to verify the MSTP instance configuration.


nfvis# show switch spanning-tree mstp configuration instance-list 
INSTANCE  VLANS MAPPED      STATE    
-------------------------------------
0         1,2350-2353,2363  enabled  
1         15                enabled

To display the global information for MSTP instance 2 use show switch spanning-tree mstp summary instance-global-info command.

To display interface information for MSTP instance 2 use show switch spanning-tree mstp summary instance-interface-info 2 command