Port rate limiting

Port rate limiting helps control undesirable traffic. Its purpose is to allow enough broadcast, multicast, and ICMP rate-limit traffic for the network to function properly, while preventing flooding and traffic storms.

A certain amount of each type of traffic is required for normal network operation. Broadcast packets may include ARP and DHCP traffic, for instance. Video streams, and certain types of network protocol packets, are multicasts. Unknown-unicast packets may be intended for devices whose addresses have temporarily aged out of network-forwarding caches. Configuring rate limits can help provide the balance between necessary and flooded traffic.