R0106-HP MSR Router Series Layer 2 - LAN Switching Configuration Guide(V7)

Task Command

Display the loop detection configuration and status. display loopback-detection

Loop detection configuration example

Network requirements

As shown in Figure 25, configure loop detection on Router A, so that Router A generates a log as a

notification and automatically shuts down the port on which a loop is detected.

Figure 25 Network diagram

Configuration procedure

1. Configure Router A:

# Create VLAN 100, and globally enable loop detection for the VLAN.

<RouterA> system-view

[RouterA] vlan 100

[RouterA-vlan100] quit

[RouterA] loopback-detection global enable vlan 100

# Configure GigabitEthernet 2/1/1 and GigabitEthernet 2/1/2 as trunk ports, and assign them

to VLAN 100.

[RouterA] interface GigabitEthernet 2/1/1

[RouterA-GigabitEthernet2/1/1] port link-type trunk

[RouterA-GigabitEthernet2/1/1] port trunk permit vlan 100

[RouterA-GigabitEthernet2/1/1] quit

[RouterA] interface gigabitethernet 2/1/2

[RouterA-GigabitEthernet2/1/2] port link-type trunk

[RouterA-GigabitEthernet2/1/2] port trunk permit vlan 100

[RouterA-GigabitEthernet2/1/2] quit

GE2/1/1

Router A

Router B Router C

GE2/1/2

VLAN 100