Information
The Cisco router must be configured to have Internet Control Message Protocol (ICMP) redirect messages disabled on all external interfaces.
GROUP ID: V-216748RULE ID: SV-216748r856439
The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Routers 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.
Solution
Disable ICMP redirects on all external interfaces as shown in the example below.
RP/0/0/CPU0:R3(config)#int g0/0/0/1RP/0/0/CPU0:R3(config-if)#no ipv4 redirects