EVPN Duplicate MAC Detection Exclusion Lists

Benefits of MAC Exclusion List for Duplicate Detection

• Prevents legitimate MAC address movements from being flagged as duplicates, ensuring smooth network operations without unnecessary traffic disruptions.

• Enhances network reliability and robustness by accurately distinguishing between genuine duplicate MAC situations and legitimate MAC mobility scenarios.

• Enables precise control over MAC address exclusion by supporting configuration with prefix lengths, facilitating the management of MAC address ranges rather than individual addresses.

• Provides granular control over MAC address monitoring by enabling the binding of exclusion lists to specific EVPN instances, facilitating precise network management.

Overview

The MAC Exclusion List for Duplicate Detection feature in EVPN environments gives you the ability to exclude specific MAC addresses from being flagged as duplicates. This is particularly useful in scenarios where frequent and legitimate MAC address movements occur, such as in redundant configurations using VRRP virtual MACs. By configuring an exclusion list, you ensure that necessary traffic movements are not mistakenly identified as duplicate MAC addresses, thus preventing unnecessary network disruptions and maintaining smooth operations.

To configure the MAC Exclusion List, use the CLI command set protocols evpn mac-list list_name mac-address mac_address_with_prefix_len. With this command you define a list of MAC addresses, with prefix lengths for more granular control. For example, to exclude a range of MAC addresses, you might enter set protocols evpn mac-list test mac-address 00:00:00:00:00:01/24. Once the MAC list is defined, you can bind it to a specific EVPN instance using the command set routing-instances instance_name protocols evpn duplicate-mac-detection exclude-list list_name. This binding ensures that the exclusion logic is applied only where necessary, preventing unintended impacts on unrelated instances.

Action commands such as set routing-instances instance_name protocols evpn duplicate-mac-detection action block or shutdown allow you to dictate specific actions when a MAC address is marked as a duplicate. These commands offer flexibility in handling duplicate MAC addresses, letting you choose to block the MAC or shut down the port. Show commands like show evpn mac-lists and show evpn instance extensive help in diagnosing and managing the MAC lists and their bindings.

Please refer to Feature Explorer for a complete list of the products that support this feature.

Configuration and Management

Use the set protocols evpn mac-list statement to create one or more MAC Exclusion Lists. A single mac-list can be bound to different EVPN instances. But each EVPN instance can only use one mac-list.

Use the set protocols evpn duplicate-mac-detection exclude-list statement to bind the list to an EVPN Instance.

QFX5K platforms supporting the default-switch-instance:

Platforms supporting routing instances:

You can view the configured MAC lists and their instance bindings with the following commands:

show evpn mac-lists

show evpn instance extensive

Additionally, a commit check in the system prevents configuration conflicts. It ensures you don't configure duplicate-mac-detection no-mac-suppression and duplicate-mac-detection exclude-list statements simultaneously. These statements serve similar functions but differ in logging. This check maintains your network configuration's integrity.

Usage Scenarios

When using the MAC Exclusion List for Duplicate Detection, it is essential to understand the behavior of the system in different scenarios. For example, if a MAC address is added to the exclusion list after being marked as a duplicate, the duplicate state will be cleared automatically. Conversely, if a MAC address is removed from the exclusion list, it will be subject to duplicate detection again if it moves. This dynamic handling ensures that the MAC Exclusion List remains effective in both preventing false positives and maintaining accurate duplicate detection.

By understanding and utilizing these configurations, you can effectively manage MAC address movements in your network, ensuring stability and performance in environments with frequent legitimate MAC movements.

Table 1 lists the expected behaviors for each scenario .

Table 1: MAC Exclusion List Scenarios

Scenario	Marked as Duplicate	Expected Behavior
MAC address added to an exclude list after the MAC is marked as a duplicate.	Yes	Clear the MAC mobility record and the duplicate state on the system.
MAC address removed from an exclude list.	Yes	Clear the MAC mobility history.
MAC address added to an exclude list before the MAC is marked as duplicate.	No	Clear the MAC mobility history
MAC address removed from an exclude list before it reaches the duplicate detect threshold limit.	No	Clear the MAC mobility history