CISC-RT-000170 - The Cisco switch must be configured to have Internet Control Message Protocol (ICMP) unreachable messages disabled on all external interfaces.

Information

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. Host unreachable ICMP messages are commonly used by attackers for network mapping and diagnosis.

Solution

Disable ip unreachables on all external interfaces as shown below:

SW1(config)# int e2/7
SW1(config-if)# no ip unreachables
SW1(config-if)# end

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_NX-OS_Switch_Y24M10_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-5, CAT|II, CCI|CCI-002385, Rule-ID|SV-221084r999693_rule, STIG-ID|CISC-RT-000170, STIG-Legacy|SV-110987, STIG-Legacy|V-101883, Vuln-ID|V-221084

Plugin: Cisco

Control ID: c59f029c5af2ac4c21e54bf18ae2145990108b5b9464b03ad7683eea61768202