ALM-303046966 MAC address flapping occurs and the interface is blocked

Description

L2IFPPI/4/MFLPIFBLOCK:OID [OID] Loop exist in vlan [INTEGER], Interface [OCTET] blocked, block-time is [GAUGE] for [OCTET], Mac Address is [OCTET].

MAC address flapping occurs and the interface is blocked.

Attribute

Parameters

Impact on the System

Traffic cannot be received normally.

Possible Causes

Cause 1: The interfaces where loops occur are added to the same VLAN.

Cause 2: Cables are connected incorrectly.

Cause 3: Loop detection and STP are enabled to remove loops on the network.

Procedure

1. Check that cables are connected correctly. Then check whether the alarm is still reported.
   • If yes, go to step 2.
   • If not, go to step 9.

2. Check whether the two interfaces that learn the same MAC address can be added to different VLANs according to the networking.
   • If yes, go to step 3.
   • If not, go to step 4.

3. Modify the configuration and add the two interfaces that learn the same MAC address to different VLANs. Then check whether the alarm is still reported.
   • If yes, go to step 4.
   • If not, go to step 9.

4. Check whether the ring network meets requirements.
   • If yes, go to step 7.
   • If not, go to step 5.

5. Do as follows to remove loops:
   1. Run the display loop-detect eth-loop [ vlan vlan-id ] command to view the blocked interface.
   2. Run the display mac-address vlan vlan-id command to search an interface that learns the MAC address.
   3. Shut down one interface according to the networking.
   4. Run the reset loop-detect eth-loop vlan vlan-id { all | interface interface-type interface-number | mac-address mac-address } command to delete the blocked interface.

6. Check whether the traffic transmission is normal.
   • If yes, go to step 9.
   • If not, go to step 7.

7. Disable loop detection and enable STP. Then check whether the alarm is still reported.
   • If yes, go to step 8.
   • If not, go to step 9.

8. Contact technical support personnel.
9. End.

Related Information

None