The network element must ensure that ICMPv6 unreachable notifications and redirects are disabled on all external facing interfaces.

From Perimeter Router Security Technical Implementation Guide

Part of Disable vulnerable ICMP messages on external int.

SV-15320r1_rule The network element must ensure that ICMPv6 unreachable notifications and redirects are disabled on all external facing interfaces.

Vulnerability discussion

The Internet Control Message Protocol version 6 (ICMPv6) supports IPv6 traffic by relaying information about paths, routes, and network conditions. Routers automatically send ICMPv6 messages under a wide variety of conditions. ICMPv6 messages are commonly used by attackers for network mapping and diagnosis: Host unreachable, and Redirect.

Check content

Review the active configuration to determine if controls have been defined to ensure router has ICMPv6 unreachables or redirects disabled any external interfaces.

Fix text

The network element configuration must be changed to ensure ICMPv6 unreachables and redirects are disabled at all external interfaces.

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