3-75
Multiple Instance Spanning-Tree Operation
Loop Protection
Loop Protection in Port Mode
To enable loop protection in port mode, follow these steps.
1. Configure port mode with this command:
HP Switch(config)# loop-protect mode port
2. Enter the loop-protect command and specify the port(s) on which loop 
protection should be enabled. For example:
HP Switch(config)# loop-protect 1-2
3. You can optionally specify a receiver-action of send-disable to shut down 
the port in the event of a loop. For example:
HP Switch(config)# loop-protect 1-2 receiver-action 
send-disable   
Loop Protection in VLAN Mode
You can only configure VLANs for loop protection when operating in VLAN 
mode. When loop-protect is enabled for a VLAN and a loop-protect enabled 
interface is a member of that VLAN, loop protect packets are sent on that VLAN 
to detect loops. 
To enable loop protection in VLAN mode, follow these steps.
1. Configure VLAN mode with this command:
HP Switch(config)# loop-protect mode vlan
2. Enter the loop-protect command and specify the VLANs on which loop 
protection should be enabled. For example:
HP Switch(config)# loop-protect vlan 20,30
Changing Modes
When changing from VLAN mode to port mode, you are prompted with a 
message, as shown in Figure 3-35. The VLANs will no longer be configured for 
loop-protection.
Configure the VLANs on which loop-protect is enabled.
Maximum number of loop-protected VLANS is 32.