Check: CISC-RT-000236
Cisco IOS XE Router RTR STIG:
CISC-RT-000236
(in versions v2 r9 through v2 r1)
Title
The Cisco router must be configured to advertise a hop limit of at least 32 in Router Advertisement messages for IPv6 stateless auto-configuration deployments. (Cat III impact)
Discussion
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.
Check Content
Review the router configuration to determine if the hop limit has been configured for Router Advertisement messages as shown in the example. ipv6 hop-limit 128 If it has been configured and has not been set to at least 32, it is a finding.
Fix Text
Configure the router to advertise a hop limit of at least 32 in Router Advertisement messages. R1(config)#ipv6 hop-limit 128
Additional Identifiers
Rule ID: SV-230039r647454_rule
Vulnerability ID: V-230039
Group Title: SRG-NET-000512-RTR-000012
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000366 |
The organization implements the security configuration settings. |
Controls
Number | Title |
---|---|
CM-6 |
Configuration Settings |