Configuring MAD
When you configure MAD, follow these restrictions and guidelines:
You can configure a minimum of one MAD mechanism on an IRF fabric for prompt IRF split detection.
Do not configure LACP MAD together with ARP MAD or ND MAD, because they handle collisions differently.
Do not configure BFD MAD together with ARP MAD or ND MAD. BFD MAD is mutually exclusive with the spanning tree feature, but ARP MAD and ND MAD require the spanning tree feature. At the same time, BFD MAD handles collisions differently than ARP MAD and ND MAD.
If LACP MAD, ARP MAD, or ND MAD runs between two IRF fabrics, assign each fabric a unique IRF domain ID. (For BFD MAD, this task is optional.)
An IRF fabric has only one IRF domain ID. You can change the IRF domain ID by using the following commands: irf domain, mad enable, mad arp enable, or mad nd enable. The IRF domain IDs configured by using these commands overwrite each other.
To prevent a port or interface from being shut down when the IRF fabric transits to the Recovery state, use the mad exclude interface command. To bring up ports and interfaces in a Recovery-state IRF fabric, use the mad restore command instead of the undo shutdown command. The mad restore command activates the Recovery-state IRF fabric.