Filter
Top Products
1-36
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
<Sysname> system-view
[Sysname] stp interface Ethernet 1/0/1 root-protection
2) Perform this configuration in Ethernet port view
<Sysname> system-view
[Sysname] interface Ethernet 1/0/1
[Sysname-Ethernet1/0/1] stp root-protection
Configuring Loop Guard
A switch maintains the states of the root port and other blocked ports by receiving and processing
BPDUs from the upstream switch. These BPDUs may get lost because of network congestions or
unidirectional link failures. If a switch does not receive BPDUs from the upstream switch for certain
period, the switch selects a new root port; the original root port becomes a designated port; and the
blocked ports turns to the forwarding state. This may cause loops in the network.
The loop guard function suppresses loops. With this function enabled, if link congestions or
unidirectional link failures occur, both the root port and the blocked ports become designated ports and
turn to the discarding state. In this case, they stop forwarding packets, and thereby loops can be
prevented.