ARP rate limiting on S series switch
"An S series switch, except S1700, can limit the rate of ARP packets and ARP Miss messages.
When the switch receives many ARP packets, configure ARP packet rate limiting to prevent CPU overloading.
When the switch receives many IP packets of which the destination IP addresses cannot be resolved, the switch generates a large number of ARP Miss messages, delivers temporary ARP entries and sends may ARP request packets to the destination network. This increases CPU load and consumes bandwidth. To avoid IP packet attacks, configure ARP Miss rate limiting on the switch."