The Juniper PE router must be configured to implement Protocol Independent Multicast (PIM) snooping for each Virtual Private LAN Services (VPLS) bridge domain.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-217074	JUNI-RT-000690	SV-217074r604135_rule		Low

Description
PIM snooping provides a way to constrain multicast traffic at Layer 2. By monitoring PIM join and prune packets on each interface, the PE router is able to determine interested multicast receivers and hence will populate the layer 2 multicast-forwarding table. This enables the PE router to deliver traffic only to ports with at least one interested member within the VPLS bridge, thereby significantly reducing the volume of multicast traffic that would otherwise flood an entire VPLS bridge domain. The PIM snooping operation applies to both access circuits and pseudowires within a VPLS bridge domain.

Description

PIM snooping provides a way to constrain multicast traffic at Layer 2. By monitoring PIM join and prune packets on each interface, the PE router is able to determine interested multicast receivers and hence will populate the layer 2 multicast-forwarding table. This enables the PE router to deliver traffic only to ports with at least one interested member within the VPLS bridge, thereby significantly reducing the volume of multicast traffic that would otherwise flood an entire VPLS bridge domain. The PIM snooping operation applies to both access circuits and pseudowires within a VPLS bridge domain.

STIG	Date
Juniper Router RTR Security Technical Implementation Guide	2022-06-07

Details

Check Text ( C-18303r297090_chk )
Review the router configuration to verify that PIM snooping has been configured under the routing instance protocols hierarchy for each VPLS bridge domain as shown in the example. routing-instances { VPLS_CUST2 { instance-type vpls; interface ge-0/1/0.0; route-distinguisher 22:22; vrf-target target:22:22; } protocols { vpls { site-range 9; no-tunnel-services; site R8 { site-identifier 8; interface ge-0/1/0.0; } vpls-id 102; neighbor 8.8.8.8; } pim-snooping; } } } } If the router is not configured to implement PIM snooping for each VPLS bridge domain, this is a finding.

Check Text ( C-18303r297090_chk )

Review the router configuration to verify that PIM snooping has been configured under the routing instance protocols hierarchy for each VPLS bridge domain as shown in the example.

routing-instances {
VPLS_CUST2 {
instance-type vpls;
interface ge-0/1/0.0;
route-distinguisher 22:22;
vrf-target target:22:22;
}
protocols {
vpls {
site-range 9;
no-tunnel-services;
site R8 {
site-identifier 8;
interface ge-0/1/0.0;
}
vpls-id 102;
neighbor 8.8.8.8;
}
pim-snooping;
}
}
}
}

If the router is not configured to implement PIM snooping for each VPLS bridge domain, this is a finding.

Fix Text (F-18301r297091_fix)
Configure PIM snooping for each VPLS bridge domain as shown in the example below. [edit routing-instances VPLS_CUST2] set routing-instances VPLS_CUST2 protocols pim-snooping