Connectivity Guide

out of the Loop-Inconsistent or blocking state and transitions to an appropriate state determined by STP.
Enabling loop guard on a per-port basis enables it on all VLANs configured on the port. If you disable loop
guard on a port, it moves to the Listening state.
If you enable BPDU filter and BPDU guard on the same port, the BPDU filter configuration takes precedence. Root guard and
Loop guard are mutually exclusive. Configuring one overwrites the other from the active configuration.
1. Enable spanning-tree BPDU filter in INTERFACE mode.
spanning-tree bpdufilter enable
● To shut down the port channel interface, all member ports are disabled in the hardware.
●
To add a physical port to a port-channel already in the Error Disable state, the new member port is also disabled in the
hardware.
● To remove a physical port from a port-channel in Error Disable state, the Error Disabled state clears on this physical port.
The physical port is enabled in the hardware.
To clear the Error Disabled state:
● Use the shutdown command on the interface.
● Use the spanning-tree bpdufilter disable command to disable the BPDU guard on the interface.
● Use the spanning-tree disable command to disable STP on the interface.
2. Enable STP BPDU guard in INTERFACE mode.
spanning-tree bpduguard enable
● To shut down the port channel interface, all member ports are disabled in the hardware.
● To add a physical port to a port-channel already in the Error Disable state, the new member port is also disabled in the
hardware.
● To remove a physical port from a port-channel in Error Disable state, the Error Disabled state clears on this physical port.
The physical port is enabled in the hardware.
To clear the Error Disabled state:
● Use the shutdown command on the interface.
● Use the spanning-tree bpduguard disable command to disable the BPDU guard on the interface.
● Use the spanning-tree disable command to disable STP on the interface.
3. Set the guard types to avoid loops in INTERFACE mode.
spanning-tree guard {loop | root | none}
● loop — Set the guard type to loop.
● none — Set the guard type to none.
● root — Set the guard type to root.
BPDU filter
OS10(conf-if-eth1/1/4)# spanning-tree bpdufilter 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 :disable 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
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)
Layer 2
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