Configuring loop protection
Procedure
-
Enable loop protection on each layer 2 interface (port, LAG, or VLAN) for which loop protection is needed, with the commands
loop-protect
andloop-protect vlan
. -
Define the action to be taken when a loop is detected with the command
loop-protect action
. -
If required, change the interval at which loop protection messages are sent with the command
loop-protect transmit-interval
. -
If required, change the length of time the switch waits before re-enabling an interface with the command
loop-protect re-enable-timer
. -
Review loop protection configuration settings with the command
show loop-protect
.
Example
This example creates the following configuration:
- Enables loop protection on data port 1/1/1 and sets the loop detection action to disable the transmit port.
- Enables loop protection on LAG 25 and sets the loop detection action to disable both transmit and receive ports.
- Enables loop protection on VLANs 100-125 and 200.
- Sets the re-enable timer to 10 seconds.
- Sets the transmit-interval to 30 seconds.
switch(config)# interface 1/1/1
switch(config-if)# no routing
switch(config-if)# loop-protect
switch(config-if)# loop-protect action tx-disable
switch(config-if)# exit
switch(config)# interface lag 25
switch(config-lag-if)# loop-protect
switch(config-if)# loop-protect action tx-rx-disable
switch(config-if)# loop-protect vlan 100-125,200
switch(config-if)# exit
switch(config)# loop-protect re-enable-timer 30
switch(config)# exit
switch# show loop-protect
Status and Counters - Loop Protection Information
Transmit Interval : 30 (sec)
Port Re-enable Timer : 10 (sec)
Interface 1/1/1
Loop-protect enabled : Yes
Loop-Protect enabled VLANs :
Action on loop detection : TX disable
Loop detected count : 0
Loop detected : No
Interface status : up
Interface lag 25
Loop-protect enabled : Yes
Loop-Protect enabled VLANs : 100-125,200
Action on loop detection : TX-RX disable
Loop detected count : 0
Loop detected : No
Interface status : up