MAC Flapping ACI

[JlassiAhmed0345]

Hi ,

I have an issue with MAC flapping in a Huawei switch. As mentioned below ( schema 2) , In our network setup, two ACI Leafs (TOR0704-BIE & TOR0703-BIE) are directly connected via a Port Channel to two Huawei switches. For Layer 3 connectivity, we configured a sub-interface on VLAN 3009 on both Leafs and assigned a secondary IP address to act as a VIP between the two Leafs. A static route is then configured on the Huawei switches to point to this VIP. SVI 3009 is used as the Layer 3 interface on the Huawei switches. The issue we're facing is MAC flapping on the Huawei switches: they detect the MAC address "00:22:BD:F8:19
" associated with the logical interface profile on both Eth-Trunk99 and the Peer-Link (Schema 1).

have any one an idea how to resolve this issue ?

Schema 1

Schema 2 

[AshSe]

Hello @JlassiAhmed0345  

MAC flapping occurs when a switch receives packets with the same source MAC address on different ports, causing instability in the network. In your case, the MAC address "00:22:BD:F8:19" is flapping between Eth-Trunk99 and the Peer-Link on the Huawei switches. This typically indicates a loop or misconfiguration in the network.

Here are some steps to troubleshoot and resolve the issue:

1. Check Port Channel Configuration: Ensure that the Port Channel (Eth-Trunk99) configuration on both the Huawei switches and the ACI Leafs is consistent and correctly configured. Verify that the member ports are correctly assigned and that the Port Channel is up and running.

2. Verify VLAN Configuration: Ensure that VLAN 3009 is correctly configured and allowed on all relevant trunks and Port Channels. Check that the VLAN is not being pruned or blocked on any of the links.

3. Examine the Peer-Link: The Peer-Link between the Huawei switches should be configured correctly to handle the traffic. Ensure that the Peer-Link is not causing a loop by incorrectly forwarding traffic that should be handled by the Port Channel.

4. Check for Spanning Tree Protocol (STP) Issues: Ensure that STP is correctly configured and that there are no STP topology changes causing the MAC address to be learned on different ports. Verify the STP status and root bridge configuration to ensure there are no loops.

5. Review ACI Configuration: On the ACI Leafs, ensure that the sub-interface on VLAN 3009 and the VIP configuration are correct. Verify that the secondary IP address and VIP are correctly configured and that there are no misconfigurations causing the MAC address to be advertised incorrectly.

6. Static MAC Address Configuration: As a temporary measure, you can configure a static MAC address entry on the Huawei switches to bind the MAC address "00:22:BD:F8:19" to the correct interface. This can help stabilize the network while you troubleshoot the root cause.

   Example command on Huawei switch:

   mac-address static 00:22:BD:F8:19 vlan 3009 interface Eth-Trunk99

7. Check for Duplicate IP Addresses: Ensure that there are no duplicate IP addresses in the network that could be causing the MAC address to be learned on different ports.

8. Monitor Traffic: Use network monitoring tools to capture and analyze traffic on the relevant interfaces. This can help identify any anomalies or unexpected traffic patterns that could be causing the MAC flapping.

By systematically checking these areas, you should be able to identify and resolve the root cause of the MAC flapping issue. If the problem persists, consider involving Huawei support for further assistance, as they can provide more in-depth analysis and troubleshooting specific to their hardware and software.

Happy Troubleshooting!!!

AshSe

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