The Juniper multicast Rendezvous Point (RP) router must be configured to filter Protocol Independent Multicast (PIM) Join messages received from the Designated Juniper router (DR) for any undesirable multicast groups.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-217087	JUNI-RT-000830	SV-217087r604135_rule		Low

Description
Real-time multicast traffic can entail multiple large flows of data. An attacker can flood a network segment with multicast packets, over-using the available bandwidth and thereby creating a denial-of-service (DoS) condition. Hence, it is imperative that join messages are only accepted for authorized multicast groups and sources.

STIG	Date
Juniper Router RTR Security Technical Implementation Guide	2024-06-12

Details

Check Text ( C-18316r297129_chk )
Review the RP router configuration to determine if it filters PIM join messages for any reserved multicast groups. Step 1: Verify that a PIM import statement has been configured as shown in the example below: protocols { … … … } pim { import MULTICAST_JOIN_POLICY; Step 2: Verify that the join policy has defined both bad multicast groups and sources as shown in the example below: policy-options { … … … } policy-statement MULTICAST_JOIN_POLICY { term BAD_GROUPS { from { route-filter 224.1.1.0/24 orlonger; route-filter 225.1.2.3/32 exact; … … … route-filter 232.0.0.0/8 orlonger; } then reject; } term ALLOW_OTHER { then accept; } } If the RP router peering with PIM-SM routers is not configured with a PIM import policy to block join messages for any undesirable multicast groups, this is a finding.

Check Text ( C-18316r297129_chk )

Review the RP router configuration to determine if it filters PIM join messages for any reserved multicast groups.

Step 1: Verify that a PIM import statement has been configured as shown in the example below:

protocols {
…
…
…
}
pim {
import MULTICAST_JOIN_POLICY;

Step 2: Verify that the join policy has defined both bad multicast groups and sources as shown in the example below:

policy-options {
…
…
…
}
policy-statement MULTICAST_JOIN_POLICY {
term BAD_GROUPS {
from {
route-filter 224.1.1.0/24 orlonger;
route-filter 225.1.2.3/32 exact;
…
…
…
route-filter 232.0.0.0/8 orlonger;
}
then reject;
}
term ALLOW_OTHER {
then accept;
}
}
If the RP router peering with PIM-SM routers is not configured with a PIM import policy to block join messages for any undesirable multicast groups, this is a finding.

Fix Text (F-18314r297130_fix)
RP routers that are peering with customer PIM-SM routers must implement a PIM import policy to block join messages for any undesirable multicast groups. Step 1: Configure a multicast join policy to filter bad groups and sources as shown in the example below: [edit policy-options policy-statement MULTICAST_JOIN_POLICY] set term BAD_GROUPS from route-filter 224.1.1.0/24 orlonger set term BAD_GROUPS from route-filter 225.1.2.3/32 exact … … … set term BAD_GROUPS then reject set term ALLOW_OTHER then accept Step 2: Configure PIM to enable the join policy as shown in the example below: [edit protocols pim] set import MULTICAST_JOIN_POLICY

Fix Text (F-18314r297130_fix)

RP routers that are peering with customer PIM-SM routers must implement a PIM import policy to block join messages for any undesirable multicast groups.

Step 1: Configure a multicast join policy to filter bad groups and sources as shown in the example below:

[edit policy-options policy-statement MULTICAST_JOIN_POLICY]
set term BAD_GROUPS from route-filter 224.1.1.0/24 orlonger
set term BAD_GROUPS from route-filter 225.1.2.3/32 exact
…
…
…
set term BAD_GROUPS then reject
set term ALLOW_OTHER then accept

Step 2: Configure PIM to enable the join policy as shown in the example below:

[edit protocols pim]
set import MULTICAST_JOIN_POLICY