CPU Rate Limiters
The Supervisor Engine 720 (SUP720) is available for high-end Catalyst 6500/7600 series switches and supports several integrated security features, including one that is important to mention. SUP720 has built-in "special case" CPU rate limiters to classify traffic that cannot be categorized otherwise. The built-in special case CPU rate limiters use an access list (examples include IP options cases, time to live [TTL] and maximum transmission unit [MTU] failure cases, and packets with errors). The CPU rate limit is mainly used for DoS protection.