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V-237760

CAT II (Medium)

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

Rule ID

SV-237760r999764_rule

STIG

Cisco NX OS Switch RTR Security Technical Implementation Guide

Version

V3R4

CCIs

CCI-000366

Discussion

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.

Check Content

Review the switch configuration to verify that Router Advertisements are suppressed on all external IPv6-enabled interfaces as shown in the example below.

interface Ethernet1/1
  no switchport
  ipv6 address 2001::1:24:3/64
  ipv6 nd suppress-ra
  no shutdown 


If the switch is not configured to suppress Router Advertisements on all external IPv6-enabled interfaces, this is a finding.

Fix Text

Configure the switch to suppress Router Advertisements on all external IPv6-enabled interfaces as shown in the example below.

SW1(config)#  interface e1/1
SW1(config-if-range)#  ipv6 nd suppress-ra
SW1(config-if-range)#  end