API Guide

○ If no BPDU is received from a remote device which was sending BPDUs, loop guard places the port in the Loop-
Inconsistent Blocking state and no traffic forwards on the port.
● When used in a Rapid-PVST network, STP loop guard performs per-port or per port-channel at a VLAN level. If no
BPDUs are received on a port-channel interface, the port or port-channel transitions to a Loop-Inconsistent or Blocking
state only for this VLAN.
BPDU filter
os10(conf-if-eth1/1/7)# spanning-tree bpdufilter enable
os10(conf-if-eth1/1/7)# do show spanning-tree interface ethernet 1/1/7
ethernet1/1/7 of vlan 1 is Designated Forwarding
Edge port: No (default)
Link type: point-to-point (auto)
Boundary: No, Bpdu-filter: Enable, Bpdu-Guard: Disable, Shutdown-on-Bpdu-Guard-
violation: No
Root-Guard: Disable, Loop-Guard: Disable
Bpdus (MRecords) Sent: 6, Received: 6410
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
-----------------------------------------------------------------------------------------
--
ethernet1/1/7 128.56 128 500 FWD 500 32769 90b1.1cf4.a625 128.56
BPDU guard
os10(config)# interface ethernet 1/1/7
os10(conf-if-eth1/1/7)# spanning-tree bpduguard enable
os10(conf-if-eth1/1/7)# do show spanning-tree interface ethernet 1/1/7
ethernet1/1/7 of vlan 1 is Designated Forwarding
Edge port: No (default)
Link type: point-to-point (auto)
Boundary: No, Bpdu-filter: Enable, Bpdu-Guard: Enable, Shutdown-on-Bpdu-Guard-violation:
Yes
Root-Guard: Disable, Loop-Guard: Disable
Bpdus (MRecords) Sent: 6, Received: 6410
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID
PortID
-----------------------------------------------------------------------------------------
----
ethernet1/1/7 128.56 128 500 FWD 500 32769 90b1.1cf4.a625
128.56
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-eth1/1/7)# spanning-tree guard root
os10(conf-if-eth1/1/7)# do show spanning-tree interface ethernet 1/1/7
ethernet1/1/7 of vlan 1 is Designated Forwarding
Edge port: No (default)
Link type: point-to-point (auto)
Boundary: No, Bpdu-filter: Enable, Bpdu-Guard: Enable, Shutdown-on-Bpdu-Guard-violation:
Yes
Root-Guard: Enable, Loop-Guard: Disable
Bpdus (MRecords) Sent: 6, Received: 6410
Interface Designated
468
Layer 2