Verifying an EtherChannel
Some typical commands for verifying include:
■ #show running-config interface number
■ #show interfaces number etherchannel
■ #show etherchannel number port-channel
■ #show etherchannel summary
Additional Spanning Tree Features
Some additional features available to help you tune Spanning Tree include:
■ BPDU Guard
■ BPDU Filtering
■ Root Guard
■ UDLD
■ Loop Guard
BPDU Guard
BPDU Guard is used to prevent loops if another switch is attached to a
Portfast port. When BPDU Guard is enabled on an interface, it is put into an
error-disabled state (basically, shut down) if a BPDU is received on the
interface. It can be enabled at either global config mode—in which case it
affects all Portfast interfaces, or at interface mode. Portfast does not have to
be enabled for it to be configured at a specific interface. The following
configuration example shows BPDU guard being enabled.
(config)#spanning-tree portfast bpduguard default
(config-if)#spanning-tree bpduguard enable