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

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.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

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_Y21M10_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-5, CAT|II, CCI|CCI-002385, Rule-ID|SV-221084r622190_rule, STIG-ID|CISC-RT-000170, STIG-Legacy|SV-110987, STIG-Legacy|V-101883, Vuln-ID|V-221084

Plugin: Cisco

Control ID: 59b21f7aa9e229ae2285baee81e357c5713ab41587429d2d707b134168849390