The Juniper router must be configured to advertise a hop limit of at least 32 in Router Advertisement messages for IPv6 stateless auto-configuration deployments.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-254071	JUEX-RT-000990	SV-254071r844246_rule		Low

Description
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.

STIG	Date
Juniper EX Series Switches Router Security Technical Implementation Guide	2023-03-23

Details

Check Text ( C-57523r844244_chk )
This requirement is not applicable for the DODIN Backbone. Review the router configuration to determine if the hop limit has been configured for Router Advertisement messages. Verify each interface configured for router advertisements contains a hop limit of at least 32. [edit protocols] router-advertisement { interface ge-0/0/0.0 { : current-hop-limit 32; <<< Supported values: 0 - 255 : } } If it has been configured and has not been set to at least 32, it is a finding.

Check Text ( C-57523r844244_chk )

This requirement is not applicable for the DODIN Backbone.

Review the router configuration to determine if the hop limit has been configured for Router Advertisement messages. Verify each interface configured for router advertisements contains a hop limit of at least 32.

[edit protocols]
router-advertisement {
interface ge-0/0/0.0 {
:
current-hop-limit 32; <<< Supported values: 0 - 255
:
}
}

If it has been configured and has not been set to at least 32, it is a finding.

Fix Text (F-57474r844245_fix)
Configure the router to advertise a hop limit of at least 32 in Router Advertisement messages. set protocols router-advertisement interface current-hop-limit <32 or greater>