Configuring MAC Address Safety

You can limit the number of MAC addresses to be learned and the rate of MAC address learning and specify the action to be taken when MAC address learning exceeds the limit.

Context

After a VSI receives a frame, if an entry that matches the destination address cannot be found in the MAC address table, the frame is regarded as an unknown frame. Unknown frames can be unknown unicast frames, unknown multicast frames, or unknown multicast frames.

A provider edge (PE) processes broadcast packets in the following mode, and the processing mode is unchangeable:

If a PE receives broadcast packets from a local user, the PE forwards the packets to other AC interfaces and other PEs on the same VPLS network.
If a PE receives broadcast packets from a remote PE, the PE forwards the packets only to AC interfaces on the same VPLS network.
A PE discards excess broadcast packets.

If the VSI has already learned MAC addresses before MAC address learning limits are configured, run the reset mac-address command in the system view to clear those addresses; otherwise, MAC address learning cannot be accurately limited.

Procedure

Run system-view
The system view is displayed.
Run vsi vsi-name [ static | auto ]
The VSI view is displayed.
Run mac-limit { action { discard | forward } | maximum maxValue rate interval } ^*
MAC address learning limits are configured.

When max and interval are set to 0, the maximum number of MAC addresses to be learned and the highest rate of MAC address learning are not limited.

After MAC address learning limits are configured, the system checks the number of learned MAC addresses before learning a new MAC address. If the number of learned MAC addresses reaches the limit, the system does not learn the new MAC address.

discard indicates that packets with new MAC addresses are discarded after the number of learned MAC addresses reaches the limit. forward indicates that packets with new MAC addresses are forwarded after the number of learned MAC addresses reaches the limit, but the new MAC addresses are not added to the MAC address table.
Run unknown-frame { unicast { broadcast | drop [ mac-learning ] } | multicast { broadcast | drop } }
Specifies the processing mode for received unknown frames.
Run commit
The configuration is committed.