The Cisco perimeter router must be configured to suppress Router Advertisements on all external IPv6-enabled interfaces.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-230046	CISC-RT-000391	SV-230046r533007_rule		Medium

Description
Many of the known attacks in stateless autoconfiguration are defined in RFC 3756 were present in IPv4 ARP attacks. To mitigate these vulnerabilities, links that have no hosts connected such as the interface connecting to external gateways must be configured to suppress router advertisements.

STIG	Date
Cisco IOS XR Router RTR Security Technical Implementation Guide	2020-09-23

Details

Check Text ( C-32354r533003_chk )

This requirement is not applicable for the DODIN Backbone. Review the router configuration to verify that Router Advertisements are suppressed on all external IPv6-enabled interfaces as shown in the example below. interface gigabitethernet1/0 ipv6 address 2001::1:0:22/64 ipv6 nd ra suppress If the router is not configured to suppress Router Advertisements on all external IPv6-enabled interfaces, this is a finding.

Fix Text (F-32331r533004_fix)
Configure the router to suppress Router Advertisements on all external IPv6-enabled interfaces as shown in the example below. R1(config)#int g1/0 R1(config-if)#ipv6 nd ra suppress R1(config-if)#end