CLI Guide

8.3.16.1 Introduced on the MXL 10/40GbE Switch IO Module..
Usage Information
If you enable portfast bpduguard on an interface and the interface receives a
BPDU, the software disables the interface and sends a message stating that fact.
The port is in ERR_DISABLE mode, yet appears in the show interface
commands as enabled. If you do not enable shutdown-on-violation, BPDUs
still are sent to the RPM CPU.
STP root guard is supported on a port or port-channel enabled in any Spanning
Tree mode: Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP),
Multiple Spanning Tree Protocol (MSTP), and Per-VLAN Spanning Tree Plus (PVST
+).
Root guard is supported on any STP-enabled port or port-channel except when
used as a stacking port. When enabled on a port, root guard applies to all VLANs
configured on the port.
1452
Spanning Tree Protocol (STP)