Adapting forwarding database learning rate based on fill level of forwarding table

A network device, comprising:

• a memory configured to store a forwarding table that includes associations between network addresses and network interfaces of, or coupled to, the network device;
• and
• a packet processor configured to process packets received via the network interfaces and to determine, using the forwarding database, network interfaces to which the packets are to be forwarded for transmission, the packet processor including:
• a fill level monitor configured to determine a fill level of the forwarding table, and
• a forwarding table updating engine configured to:
• adjust, based on the fill level of the forwarding table, a maximum rate according to which the packet processor is permitted to send messages to a central processing unit (CPU) coupled to the packet processor, the messages indicating network addresses that are to be stored in the forwarding table by the CPU,
• identify new network addresses of packets received via the network interfaces that are not in the forwarding table, and
• send to the CPU, at a rate that does not exceed the maximum rate, messages that indicate the new network addresses are to be added to the forwarding table, the CPU being configured to selectively add the new network addresses to the forwarding table.