The Juniper multicast Designated Router (DR) must be configured to filter the IGMP and MLD Report messages to allow hosts to join only multicast groups that have been approved by the organization.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-254050	JUEX-RT-000780	SV-254050r844262_rule		Low

Description
Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., someone downloading a file here or there), whereas multicast can have broader impact on bandwidth consumption, resulting in extreme network congestion. Hence, it is imperative that there is multicast admission control to restrict which multicast groups hosts are allowed to join via IGMP or MLD.

Description

Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., someone downloading a file here or there), whereas multicast can have broader impact on bandwidth consumption, resulting in extreme network congestion. Hence, it is imperative that there is multicast admission control to restrict which multicast groups hosts are allowed to join via IGMP or MLD.

STIG	Date
Juniper EX Series Switches Router Security Technical Implementation Guide	2024-06-10

Details

Check Text ( C-57502r844181_chk )
Review the configuration of the DR to verify that it is filtering IGMP or MLD report messages, allowing hosts to join only those groups that have been approved. Note: This requirement is only applicable to Source Specific Multicast (SSM) implementation. This requirement is not applicable to Any Source Multicast (ASM) since the filtering is being performed by the Rendezvous Point router. [edit policy-options] policy-statement { term unauth-groups { from { route-filter 224.0.1.2/32 exact; route-filter 224.0.2.2/32 exact; } then reject; } term allow-others { then accept; } } policy-statement { term unauth-groups { from { route-filter fec0:1:1:4::/64 exact; } then reject; } term allow-others { then accept; } } [edit protocols] igmp { interface . { group-policy ; } } mld { interface . { group-policy ; } } If the DR is not filtering IGMP or MLD report messages, this is a finding.

Check Text ( C-57502r844181_chk )

Review the configuration of the DR to verify that it is filtering IGMP or MLD report messages, allowing hosts to join only those groups that have been approved.

Note: This requirement is only applicable to Source Specific Multicast (SSM) implementation. This requirement is not applicable to Any Source Multicast (ASM) since the filtering is being performed by the Rendezvous Point router.

[edit policy-options]
policy-statement {
term unauth-groups {
from {
route-filter 224.0.1.2/32 exact;
route-filter 224.0.2.2/32 exact;
}
then reject;
}
term allow-others {
then accept;
}
}
policy-statement {
term unauth-groups {
from {
route-filter fec0:1:1:4::/64 exact;
}
then reject;
}
term allow-others {
then accept;
}
}

[edit protocols]
igmp {
interface . {
group-policy ;
}
}
mld {
interface . {
group-policy ;
}
}

If the DR is not filtering IGMP or MLD report messages, this is a finding.

Fix Text (F-57453r844182_fix)
Configure the DR to filter the IGMP and MLD report messages to allow hosts to join only those multicast groups that have been approved. set policy-options policy-statement term unauth-groups from route-filter 224.0.1.2/32 exact set policy-options policy-statement term unauth-groups from route-filter 224.0.2.2/32 exact set policy-options policy-statement term unauth-groups then reject set policy-options policy-statement term accept-others then accept set policy-options policy-statement term unauth-groups from route-filter fec0:1:1:4::/64 exact set policy-options policy-statement term unauth-groups then reject set policy-options policy-statement term accept-others then accept set protocols igmp interface . group-policy set protocols mld interface . group-policy

Fix Text (F-57453r844182_fix)

Configure the DR to filter the IGMP and MLD report messages to allow hosts to join only those multicast groups that have been approved.

set policy-options policy-statement term unauth-groups from route-filter 224.0.1.2/32 exact
set policy-options policy-statement term unauth-groups from route-filter 224.0.2.2/32 exact
set policy-options policy-statement term unauth-groups then reject
set policy-options policy-statement term accept-others then accept

set policy-options policy-statement term unauth-groups from route-filter fec0:1:1:4::/64 exact
set policy-options policy-statement term unauth-groups then reject
set policy-options policy-statement term accept-others then accept

set protocols igmp interface . group-policy
set protocols mld interface . group-policy