Guard Topology-Change - Cisco ASR 9000 Series Reference Manual

Multiple Spanning Tree Protocol Commands

guard topology-change

To enable topology change guard on the port, use the guard topology-change command in MSTP interface
configuration submode.
guard topology-change
Syntax Description
This command has no keywords or arguments.
Command Default
TopologyChangeGuard is disabled.
Command Modes
MSTP interface configuration
Command History
Release
Release 3.7.1
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes appropriate task
IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator
for assistance.
This command enables topology change guard (also known as restricted TCN) on this interface. When this
feature is enabled, topology changes originating at this interfaces, or received in BPDUs on this interface, are
not propagated to the rest of the MSTP network. For more information on guard topology, refer to the
Implementing Multiple Spanning Tree Protocol module in the Cisco ASR 9000 Series Aggregation Services
Router L2VPN and Ethernet Services Configuration Guide.
Task ID
Task ID
interface
Examples
The following example shows how to enable TopologyChangeGuard on the port:
RP/0/RSP0/CPU0:router(config-mstp-if)# guard topology-change
Related Commands
Command
debug spanning-tree mst packet, on page 479
Cisco ASR 9000 Series Aggregation Services Router VPN and Ethernet Services Command Reference, Release
Modification
This command was introduced.
Operations
read, write
Description
Enables debugging for sent and received MSTP packets.
guard topology-change
6.1.x
509