H3C Technologies H3C S3600 Series Switches - Manual (Page 289)

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You can avoid this problem by utilizing the root guard function. Ports with this function enabled can only
be kept as designated ports in all MSTIs. When a port of this type receives configuration BPDUs with
higher priorities, it turns to the discarding state (rather than become a non-designated port) and stops
forwarding packets (as if it is disconnected from the link). It resumes the normal state if it does not
receive any configuration BPDUs with higher priorities for a specified period.
z
You are recommended to enable root guard on the designated ports of a root bridge.
z
Loop guard, root guard, and edge port settings are mutually exclusive. With one of these functions
enabled on a port, any of the other two functions cannot take effect even if you have configured it
on the port.
Configuration Prerequisites
MSTP runs normally on the switch.
Configuration procedure
Follow these steps to configure the root guard function in system view:
To do... Use the command... Remarks
Enter system view system-view —
Enable the root guard function
on specified ports stp interface interface-list
root-protection
Required
The root guard function is
disabled by default.
Follow these steps to enable the root guard function in Ethernet port view:
To do... Use the command... Remarks
Enter system view system-view —
Enter Ethernet port view
Interface interface-type
interface-number
—
Enable the root guard function
on the current port
stp root-protection
Required
The root guard function is
disabled by default.
Configuration example
# Enable the root guard function on Ethernet 1/0/1.
1) Perform this configuration in system view
system-view
[Sysname] stp interface Ethernet 1/0/1 root-protection
2) Perform this configuration in Ethernet port view
system-view
[Sysname] interface Ethernet 1/0/1