The Cisco switch must be configured to advertise a hop limit of at least 32 in Switch Advertisement messages for IPv6 stateless auto-configuration deployments.
An XCCDF Rule
Description
<VulnDiscussion>The Neighbor Discovery protocol allows a hop limit value to be advertised by routers in a Router Advertisement message being used by hosts instead of the standardized default value. If a very small value was configured and advertised to hosts on the LAN segment, communications would fail due to the hop limit reaching zero before the packets sent by a host reached its destination.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-237754r999759_rule
- Severity
- Low
- References
- Updated
Remediation - Manual Procedure
Configure the switch to advertise a hop limit of at least 32 in Router Advertisement messages as shown in the example.
SW1(config)# interface e2/1 – 2
SW1(config-if-range)# ipv6 nd hop-limit 32
SW1(config-if-range)# end