Reference Guide

Boundary: NO bpdu filter : bpdu guard : bpduguard shutdown-on-
violation :disable RootGuard: disable LoopGuard enable
Bpdus (MRecords) sent 7, received 20
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
-------------------------------------------------------------------------
ethernet1/1/4 128.272 128 500 FWD 0 32769 90b1.1cf4.9d3b 128.272
Root guard
OS10(conf-if-eth1/1/4)# spanning-tree guard root
OS10(conf-if-eth1/1/4)# do show spanning-tree interface ethernet 1/1/4
ethernet1/1/4 of vlan1 is root Forwarding
Edge port:no (default) port guard :none (default)
Link type is point-to-point (auto)
Boundary: NO bpdu filter : bpdu guard : bpduguard shutdown-on-
violation :disable RootGuard: enable LoopGuard disable
Bpdus (MRecords) sent 7, received 33
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
-------------------------------------------------------------------
ethernet1/1/4 128.272 128 500 BLK 500 32769 90b1.1cf4.a911 128.272
Debug congurations
Use the debug spanning-tree bpdu command to monitor and verify that the MST conguration is communicating as congured. To
ensure all necessary parameters match — region name, region version, and VLAN to instance mapping — examine your individual devices.
Use the show spanning-tree mst command to view the MST conguration, or use the show running-configuration
command to view the overall MST conguration.
MST
ags for
communication
received from same
region
The MST routers are located in the same region. If the debug logs indicate that packets are coming from a
Dierent Region, one of the key parameters does not match.
MST region name
and revision
The congured name and revisions must be identical among all devices. If the region name is blank, a name was
congured on one device and was not congured or was congured dierently on another — spelling and
capitalization counts.
MST instances Verify the VLAN to MST instance mapping using the show commands. If you see extra MST instances in the
Sending or Received logs, an additional MST instance was congured on one router but not others.
• View BPDUs in EXEC mode.
debug spanning-tree bpdu
• View MST-triggered topology change messages in EXEC mode.
debug spanning-tree events
View MST conguration
OS10# show spanning-tree mst configuration
Region Name: force10
Revision: 100
MSTI VID
0 1,31-4093
1 2-10
2 11-20
3 21-30
MST commands
Layer 2
203