72. BPDU Guard of STP security configuration experiment

1. BPDU Guard parsing

In order to protect the stability of Spanningtree, BPDU Guard is configured on the non-switch port of the switch. When BPDU is received on the interface configured with BPDU Guard, the interface state becomes err-disabled, and the physical and link state of the interface is down.

Configuration method:

Global configuration mode: spanning-tree portfast bpduguard default

API configuration mode: spanning-tree bpduguard enable is enabled

Interface configuration mode: spanning-tree bpduguard disable is down

Recovery method:

Manual recovery: shutdown the interface after no shutdown

Automatic recovery: errdisable recovery cause bpduguard

Recovery interval: errdisable recovery interval 30

2. Configure BPDU Guard

We now turn on bgduguard on the S4 interface and set the automatic recovery interval to 30s. When we connect S1 to the e0and0 of S4, observe the state change of the interface.