[case sharing] basic function configuration of network loop detection

Configuration requirements

 

• Three devices Device A、Device B and Device C Form a physical ring network .

• By means of Device A Configure the loop detection function on , Enable the system to shut down automatically Device A The port on which the loop appears , And inform users to check the network by printing log information .

Networking diagram

chart 1-3 Network diagram of basic function configuration of loop detection

Configuration steps

(1) To configure Device A

#  establish VLAN 100, And open the global VLAN Loop detection function in .
<DeviceA> system-view
[DeviceA] vlan 100
[DeviceA–vlan100] quit
[DeviceA] loopback-detection global enable vlan 100
#  configure port GigabitEthernet1/0/1 and GigabitEthernet1/0/2 by Trunk type , And allow VLAN 100 adopt .
[DeviceA] interface gigabitethernet 1/0/1
[DeviceA-GigabitEthernet1/0/1] port link-type trunk
[DeviceA-GigabitEthernet1/0/1] port trunk permit vlan 100
[DeviceA-GigabitEthernet1/0/1] quit
[DeviceA] interface gigabitethernet 1/0/2
[DeviceA-GigabitEthernet1/0/2] port link-type trunk
[DeviceA-GigabitEthernet1/0/2] port trunk permit vlan 100
[DeviceA-GigabitEthernet1/0/2] quit
#  The processing mode of global configuration loop detection is Shutdown Pattern .
[DeviceA] loopback-detection global action shutdown
#  The time interval for configuring loop detection is 35 second .
[DeviceA] loopback-detection interval-time 3

(2) To configure Device B

#  establish VLAN 100.
<DeviceB> system-view
[DeviceB] vlan 100
[DeviceB–vlan100] quit
#  configure port GigabitEthernet1/0/1 and GigabitEthernet1/0/2 by Trunk type , And allow VLAN 100 adopt .
[DeviceB] interface gigabitethernet 1/0/1
[DeviceB-GigabitEthernet1/0/1] port link-type trunk
[DeviceB-GigabitEthernet1/0/1] port trunk permit vlan 100
[DeviceB-GigabitEthernet1/0/1] quit
[DeviceB] interface gigabitethernet 1/0/2
[DeviceB-GigabitEthernet1/0/2] port link-type trunk
[DeviceB-GigabitEthernet1/0/2] port trunk permit vlan 100
[DeviceB-GigabitEthernet1/0/2] qui

(3) To configure Device C

#  establish VLAN 100.
<DeviceC> system-view
[DeviceC] vlan 100
[DeviceC–vlan100] quit
#  configure port GigabitEthernet1/0/1 and GigabitEthernet1/0/2 by Trunk type , And allow VLAN 100 adopt .
[DeviceC] interface gigabitethernet 1/0/1
[DeviceC-GigabitEthernet1/0/1] port link-type trunk
[DeviceC-GigabitEthernet1/0/1] port trunk permit vlan 100
[DeviceC-GigabitEthernet1/0/1] quit
[DeviceC] interface gigabitethernet 1/0/2
[DeviceC-GigabitEthernet1/0/2] port link-type trunk
[DeviceC-GigabitEthernet1/0/2] port trunk permit vlan 100
[DeviceC-GigabitEthernet1/0/2] qui

Verify configuration

When configuration is complete , The system is within a loop detection interval Device A The port of GigabitEthernet1/0/1 and GigabitEthernet1/0/2 Loops have been detected on , So the two ports are automatically closed , And printed the following log information ：

[DeviceA]
%Feb 24 15:04:29:663 2013 DeviceA LPDT/4/LPDT_LOOPED: Loopback exists on GigabitEthernet1/0/1.
%Feb 24 15:04:29:665 2013 DeviceA LPDT/4/LPDT_VLAN_LOOPED: Loopback exists on GigabitEthernet1/0/1 in VLAN 100.
%Feb 24 15:04:29:667 2013 DeviceA LPDT/4/LPDT_LOOPED: Loopback exists on GigabitEthernet1/0/2.
%Feb 24 15:04:29:669 2013 DeviceA LPDT/4/LPDT_VLAN_LOOPED: Loopback exists on GigabitEthernet1/0/2 in VLAN 100.
%Feb 24 15:04:44:240 2013 DeviceA LPDT/5/LPDT_RECOVERED: Loopback on GigabitEthernet1/0/1 in VLAN 100 recovered.
%Feb 24 15:04:44:243 2013 DeviceA LPDT/5/LPDT_RECOVERED: Loopback on GigabitEthernet1/0/1 recovered.
%Feb 24 15:04:44:245 2013 DeviceA LPDT/5/LPDT_RECOVERED: Loopback on GigabitEthernet1/0/2 in VLAN 100 recovered.
%Feb 24 15:04:44:248 2013 DeviceA LPDT/5/LPDT_RECOVERED: Loopback on GigabitEthernet1/0/2 recovered

Use display loopback-detection Commands can be viewed Device A Configuration and operation of upper loop detection ：

#  Show Device A Configuration and operation of upper loop detection .
[DeviceA] display loopback-detection
Loopback detection is enabled.
Loopback detection interval is 35 second(s).
No loopback is detected.

thus it can be seen ,Device A Is not shown on the port GigabitEthernet1/0/1 and GigabitEthernet1/0/2 Loop detected on , This is because the loop detection function operates in Shutdown In mode , port GigabitEthernet1/0/1 and GigabitEthernet1/0/2 After the loop appears on the, it has been automatically closed , Therefore, the loop on these two ports has been eliminated . here , Use display interface Command to view separately Device A On the port GigabitEthernet1/0/1 and GigabitEthernet1/0/2 Status information ：

#  Show Device A On the port GigabitEthernet1/0/1 Status information .
[DeviceA] display interface gigabitethernet 1/0/1
GigabitEthernet1/0/1 current state: DOWN (Loopback detection down)
...
#  Show Device A On the port GigabitEthernet1/0/2 Status information .
[DeviceA] display interface gigabitethernet 1/0/2
GigabitEthernet1/0/2 current state: DOWN (Loopback detection down)
...

thus it can be seen , port GigabitEthernet1/0/1 and GigabitEthernet1/0/2 Have been automatically turned off by the loop detection module .

end