Application Scenarios for MAC Address Limit

MAC Address Limit on an Inbound Interface

Currently, interfaces on the NetEngine 8000 F can function as Layer 2 interfaces. A Layer 2 interface on the device can be connected to multiple Layer 2 user networks belonging to different VLANs.

You can enable MAC address limit on Layer 2 interfaces of the NetEngine 8000 F to control the total number of MAC addresses that can be learnt from all the attached user networks, regardless of the VLANs to which each user network belongs. On the network shown in Figure 1, you can configure MAC address limit on port1 of the NetEngine 8000 F.

MAC Address Limit for One or More VLANs to Which an Inbound Interface Belongs

In addition to MAC address limit on an inbound interface, you can also configure MAC address limit for one or more specific VLANs to which an inbound interface belongs.

On the network shown in Figure 1, you can configure MAC address limit based on Port+VLAN on port1 of the NetEngine 8000 F to restrict the number of MAC addresses barely on VLAN 10 or VLAN 20.

MAC Address Limit on an Inbound Sub-Interface

By default, Layer 2 forwarding is prohibited on a sub-interface. Therefore, MAC address limit cannot be configured on a sub-interface. When a sub-interface is bound to a VSI, however, Layer 2 forwarding can be implemented on the sub-interface, and thus MAC address limit can be configured on the sub-interface.

MAC Address Limit on an Inbound Sub-Interface for QinQ VLAN Tag Termination

Like any other common sub-interface, a sub-interface for QinQ VLAN tag termination needs to implement Layer 2 forwarding and be configured with MAC address limit when accessing the VPLS service. The NetEngine 8000 F allows you to set the maximum number of MAC addresses to be learnt by a sub-interface for QinQ VLAN tag termination and the forwarding behavior after the maximum number is reached, as shown in Figure 2.