Reference Guide
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
BPDU guard
OS10(config)# interface ethernet 1/1/4
OS10(conf-if-eth1/1/4)# spanning-tree bpduguard enable
OS10(conf-if-eth1/1/4)# do show spanning-tree interface ethernet 1/1/4
ethernet1/1/4 of vlan1 is designated Blocking
Edge port:no (default) port guard :none (default)
Link type is point-to-point (auto)
Boundary: NO bpdu filter : Enable bpdu guard : bpduguard shutdown-on-
violation :enable RootGuard: enable LoopGuard disable
Bpdus (MRecords) sent 134, received 138
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
Loop guard
OS10(config)# interface ethernet 1/1/4
OS10(conf-if-eth1/1/4)# spanning-tree guard loop
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: 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 congurations
Use the debug spanning-tree bpdu command to monitor and verify that the MST conguration is communicating as congured. 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 conguration, or use the show running-configuration
command to view the overall MST conguration.
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
Dierent Region, one of the key parameters does not match.
Layer 2 175