Cisco Systems A9014CFD 13-8, This example shows MST on port channels:

13-8
Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
OL-23826-09
Chapter 13 Configuring MST on EVC Bridge Domain
Contents
encapsulation dot1q 2
bridge-domain 100
!
service instance 2 ethernet
encapsulation dot1q 2 second-dot1q 100
bridge-domain 200
The preceding configuration does not affect the MSTP operation on the interface; there is no state change
for interface gi4/3 in the MST instance it belongs to.
Router# show spanning-tree mst 1
##### MST1 vlans mapped: 2
Bridge address 0009.e91a.bc40 priority 32769 (32768 sysid 1)
Root this switch for MST1
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi4/3 Desg FWD 20000 128.1540 P2p
This example shows MST on port channels:
Router# show spanning-tree mst 1
##### MST1 vlans mapped: 3
Bridge address 000a.f331.8e80 priority 32769 (32768 sysid 1)
Root address 0001.6441.68c0 priority 32769 (32768 sysid 1)
port Po5 cost 20000 rem hops 18
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi2/0/0 Desg FWD 20000 128.257 P2p
Po5 Root FWD 10000 128.3329 P2p
Po6 Altn BLK 10000 128.3330 P2p
Router# show spanning-tree vlan 3
MST1
Spanning tree enabled protocol mstp
Root ID Priority 32769
Address 0001.6441.68c0
Cost 20000
Port 3329 (Port-channel5)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 000a.f331.8e80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi2/0/0 Desg FWD 20000 128.257 P2p
Po5 Root FWD 10000 128.3329 P2p
Po6 Altn BLK 10000 128.3330 P2p