Description

This article describes a potential issue when deploying SRX chassis clusters at both ends of an L2VPN environment.

Symptoms

When two SRX clusters are deployed across an L2VPN, the network may experience:

  • MAC address flapping on intermediate Layer 2 devices
  • Intermittent packet drops or traffic instability

Solution

The issue can occur if both SRX clusters are configured with the same cluster ID. This results in duplicate MAC address generation across the clusters, which can confuse intermediate Layer 2 devices such as switches.

As a result, switches may continuously update their MAC address tables (MAC flapping), leading to forwarding inconsistencies and packet loss.

 

Example:

SRX Cluster ─── L2 Device ─── L2VPN ─── L2 Device ─── SRX Cluster

Ensure that each SRX chassis cluster in the network is configured with a unique cluster ID. This prevents MAC address conflicts across the network and avoids instability on Layer 2 devices.

Using distinct cluster IDs ensures proper MAC address learning and stable traffic forwarding across the L2VPN environment.

Modification History

2024-09-09 : Article Created