Enabling Root Guard

Enabling Root Guard

Switch2 (enable) set spantree guard root 1/1

Enable rootguard will disable loopguard if it's currently enabled on the

  port(s).

Do you want to continue (y/n) [n]? y

Switch2 (enable) 2003 Oct 07 17:40:55 %SPANTREE-5-ROOTCHANGE:Root changed for

  Vlan 2: New root port 0/0. New Root mac address is 00-01-63-29-bc-01.

2003 Oct 07 17:40:55 %SPANTREE-2-ROOTGUARDBLOCK: Port 1/1 tried to become non-

  designated in VLAN 2. Moved to root-inconsistent state

2003 Oct 07 17:40:56 %SPANTREE-6-PORTBLK: Port 1/1 state in VLAN 2 changed to

  blocking

If superior BPDUs are heard from a portfast-enabled port, the port state is changed to root inconsistent state. In Example 10-7, Switch2 heard superior BPDUs for VLAN 2 on port 1/1. Root Guard is enabled per port and affects all VLANs that traverse that port.