Users Guide

configured, the following error message is displayed: % Error: RootGuard is
configured. Cannot configure LoopGuard.
Do not enable Portfast BPDU guard and loop guard at the same time on a port.
Enabling both features may result in a port that remains in a blocking state and prevents
traffic from flowing through it. For example, when Portfast BPDU guard and loop guard
are both configured:
• If a BPDU is received from a remote device, BPDU guard places the port in an Err-
Disabled Blocking state and no traffic is forwarded on the port.
• If no BPDU is received from a remote device, loop guard places the port in a
Loop-Inconsistent Blocking state and no traffic is forwarded on the port.
To display the type of STP guard (Portfast BPDU, root, or loop guard) enabled on a port,
enter the show spanning-tree 0 command.
Spanning Tree Protocol (STP) 1954