Setup Guide

Figure 119. STP Root Guard Prevents Bridging Loops
Conguring Root Guard
Enable STP root guard on a per-port or per-port-channel basis.
Dell EMC Networking OS Behavior: The following conditions apply to a port enabled with STP root guard:
• Root guard is supported on any STP-enabled port or port-channel interface except when used as a stacking port.
• Root guard is supported on a port in any Spanning Tree mode:
– Spanning Tree Protocol (STP)
– Rapid Spanning Tree Protocol (RSTP)
– Multiple Spanning Tree Protocol (MSTP)
– Per-VLAN Spanning Tree Plus (PVST+)
• When enabled on a port, root guard applies to all VLANs congured on the port.
• You cannot enable root guard and loop guard at the same time on an STP port. For example, if you congure root guard on a port on
which loop guard is already congured, the following error message displays: • % Error: LoopGuard is configured.
Cannot configure RootGuard.
• When used in an MSTP network, if root guard blocks a boundary port in the CIST, the port is also blocked in all other MST instances.
To enable the root guard on an STP-enabled port or port-channel interface in instance 0, use the following command.
• Enable root guard on a port or port-channel interface.
INTERFACE mode or INTERFACE PORT-CHANNEL mode
spanning-tree {0 | mstp | rstp | pvst} rootguard
– 0: enables root guard on an STP-enabled port assigned to instance 0.
946
Spanning Tree Protocol (STP)