During MAC address learning, MAC address limit is used to restrict the maximum number of MAC addresses that can be learnt by an interface. The basic principles are as follows:
MAC address limit based on Port or Port+VLAN or PW
1. When a user packet passes through a port enabled with MAC address limit based on Port or Port+VLAN or PW, the NetEngine 8000 F learns the source MAC address and forwarding information carried in the user packet and experiences the limit process.
2. Limit process: The NetEngine 8000 F first determines whether the source MAC address to be learnt exists in the MAC table. If so, the packet is simply forwarded; if not, the NetEngine 8000 F checks whether the number of MAC addresses that are learnt previously reaches the maximum number set in MAC address limit. If the set maximum number is not reached, the NetEngine 8000 F learns the MAC address of the packet; If the set maximum number is reached, the NetEngine 8000 F discards or forwards the packet based on the action set in MAC address limit.
MAC address limit based on a VLAN in a broadcast domain or a VSI or on a BD
1. When a user packet is forwarded in a broadcast domain configured with MAC address limit, the NetEngine 8000 F learns the source MAC address of the packet on the outbound interface. If the source MAC address of the packet exists in the MAC table, the NetEngine 8000 F simply forwards the packet; if the source MAC address of the packet does not exist in the MAC table, the NetEngine 8000 F checks whether the number of MAC addresses learnt previously reaches the maximum number set in MAC address limit. If not, the NetEngine 8000 F learns the MAC address of the packet; if so, the NetEngine 8000 F discards or forwards the packet based on the action configured in MAC address limit.