Cisco ASR 9000 Series Configuration Guidelines

The following example shows the output from the show spanning-tree mst command, which produces more
detailed information regarding interface state than the standard command as described above:
# show spanning-tree mst a interface GigabitEthernet0/1/2/1
GigabitEthernet0/1/2/1
Cost: 20000
link-type: point-to-point
hello-time 1
Portfast: no
BPDU Guard: no
Guard root: no
Guard topology change: no
BPDUs sent 492, received 3
MST 3:
Edge port:
Boundary : internal
Designated forwarding
Vlans mapped to MST 3: 1-2,4-2999,4000-4094
Port info port id 128.193 cost 200000
Designated root address 0050.3e66.d000 priority 8193 cost 20004
Designated bridge address 0002.172c.f400 priority 49152 port id 128.193
Timers: message expires in 0 sec, forward delay 0, forward transitions 1
Transitions to reach this state: 12
The output includes interface information about the interface which applies to all MSTIs:
• Cost
• link-type
• hello-time
• portfast (including whether BPDU guard is enabled)
• guard root
• guard topology change
• BPDUs sent, received.
It also includes information specific to each MSTI:
• Port ID, priority, cost
• BPDU information from root (bridge ID, cost, and priority)
• BPDU information being sent on this port (Bridge ID, cost, priority)
• State transitions to reach this state.
• Topology changes to reach this state.
• Flush containment status for this MSTI.
This example shows the output of show spanning-tree mst errors, which produces information about interfaces
that are configured for MSTP but where MSTP is not operational. Primarily this shows information about
interfaces which do not exist:
# show spanning-tree mst a errors
Interface Error
-------------------------------
GigabitEthernet1/2/3/4 Interface does not exist.
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
454
Implementing Multiple Spanning Tree Protocol
Configuring MSTP: Examples

Cisco ASR 9000 Series Specifications

General

Series	ASR 9000
Category	Network Router
Modular Design	Yes
Redundancy	Yes (Hardware and Software)
Operating System	Cisco IOS XR
Interfaces/Ports	10G, 40G, 100G, 400G Ethernet
Expansion Slots	Varies by model
Routing Protocol	BGP, OSPF, IS-IS, EIGRP
Management	CLI, SNMP, NETCONF
Power Supply	Redundant
Port Density	Varies by model
Power Supply Options	AC, DC
Memory	Varies by model
Storage	Varies by model
Dimensions	Varies by model
Weight	Varies by model