Cisco Systems A9014CFD manual 13-7, Router# show spanning-tree vlan

Chapter 13 Configuring MST on EVC Bridge Domain

Contents

In this example, interface gi4/1 and interface gi4/3 are connected back-to-back. Each has a service instance (EFP) attached to it. The EFP on both interfaces has an encapsulation VLAN ID of 2. Changing the VLAN ID from 2 to 8 in the encapsulation directive for the EFP on interface gi4/1 stops the MSTP from running in the MST instance to which the old VLAN is mapped and starts the MSTP in the MST instance to which the new VLAN is mapped:

Router(config-if)# interface g4/1

Router(config-if)#service instance 1 ethernet

Router(config-if-srv)# encap dot1q 8

Router(config-if-srv)# end

Use this command to verify the configuration:

Router# show spanning-tree vlan 2

MST1
Spanning tree enabled protocol mstp
Root ID	Priority	32769
	Address	0009.e91a.bc40
	This bridge	is the root
	Hello Time	2 sec	Max Age 20 sec	Forward Delay 15 sec
Bridge ID	Priority	32769 (priority 32768		sys-id-ext 1)
	Address	0009.e91a.bc40
	Hello Time	2 sec	Max Age 20 sec	Forward Delay 15 sec
Interface	Role	Sts Cost	Prio.Nbr	Type

------------------- ----		--- --------- --------		--------------------------------
Gi4/3	Desg FWD 20000		128.1540 P2p
Router# show	spanning-tree vlan 8
MST2
Spanning tree enabled protocol mstp
Root ID	Priority	32770
	Address	0009.e91a.bc40
	This bridge	is the root
	Hello Time	2 sec	Max Age 20 sec	Forward Delay 15 sec
Bridge ID	Priority	32770 (priority 32768		sys-id-ext 2)
	Address	0009.e91a.bc40
	Hello Time	2 sec	Max Age 20 sec	Forward Delay 15 sec
Interface	Role	Sts Cost	Prio.Nbr	Type
------------------- ----		--- --------- --------		--------------------------------
Gi4/1	Desg FWD 20000		128.1537 P2p

In this example, interface gi4/3 (with an EFP that has an outer encapsulation VLAN ID of 2 and a bridge domain of 100) receives a new service:

Router# enable

Router# configure terminal

Router(config)# interface g4/3

Router((config-if)#service instance 2 ethernet

Router((config-if-srv)#encap dot1q 2 second-dot1q 100

Router((config-if-srv)# bridge-domain 200

Now there are two EFPs configured on interface gi4/3 and both of them have the same outer VLAN 2.

interface GigabitEthernet4/3

no ip address

service instance 1 ethernet

	Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
OL-23826-09		13-7