CISC-RT-000190 - The Cisco switch must be configured to have Internet Control Message Protocol (ICMP) redirect messages disabled on all external interfaces.
The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Switches automatically send ICMP messages under a wide variety of conditions. Redirect ICMP messages are commonly used by attackers for network mapping and diagnosis. NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
Disable ICMP redirects on all external interfaces as shown in the example below: SW1(config)# int e2/7 SW1(config-if)# no ip redirects