Guidelines for configuring ICMP rate-limiting

Apply ICMP rate-limiting on all connected interfaces on the switch to effectively throttle excessive ICMP messaging from any source. Figure 21: Example: of ICMP rate-limiting shows an Example: of how to configure this for a small to mid-sized campus though similar rate-limit thresholds are applicable to other network environments. On edge interfaces, where ICMP traffic should be minimal, a threshold of 1% of available bandwidth should be sufficient for most applications. On core interfaces, such as switch-to-switch and switch-to-router, a maximum threshold of 5% should be sufficient for normal ICMP traffic. ("Normal" ICMP traffic levels should be the maximums that occur when the network is rebooting.)