Recover BPDU Guard after error state

An access port could receive an unexpected BPDUs accidentally or because a user connected an unauthorized switch to the access port

If a BPDU is received on a BPDU Guard enabled access port, the port is put into error-disabled state

This means the port must be manually re-enabled or automatically recovered through the 

errdisable recovery cause psecure_violation 

global command

BPDU Guard can be enabled:

• On an interface – Use the spanning-tree bpduguard enable interface configuration command
• Globally – Use the spanning-tree portfast bpduguard default global configuration command to enable BPDU Guard on all access ports