Title

The RUCKUS ICX router must be configured to have Internet Control Message Protocol (ICMP) unreachable notifications disabled on all external interfaces. (Cat II impact)

Discussion

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

Check Content

Review the device configuration to determine if controls have been defined to ensure the router does not send ICMP unreachable notifications out to any external interfaces. show run verify "no ip icmp unreachable" is present If ICMP unreachable notifications are enabled on any external interfaces, this is a finding.

Fix Text

Configure the ICX to not send ICMP unreachable messages. conf t no ip icmp unreachable wr mem

Additional Identifiers

Rule ID: SV-273631r1110937_rule

Vulnerability ID: V-273631

Group Title: SRG-NET-000362-RTR-000113

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.