Title

The Juniper EX switch must be configured to enable IGMP or MLD Snooping on all VLANs. (Cat III impact)

Discussion

IGMP and MLD snooping provides a way to constrain multicast traffic at layer 2. By monitoring the IGMP or MLD membership reports sent by hosts within a VLAN, the snooping application can set up layer 2 multicast forwarding tables to deliver specific multicast traffic only to interfaces connected to hosts interested in receiving the traffic, thereby significantly reducing the volume of multicast traffic that would otherwise flood the VLAN.

Check Content

Review the switch configuration to verify that IGMP or MLD snooping has been configured for IPv4 and IPv6 multicast traffic respectively. Verify IGMP and MLD is globally configured for all VLANs: [edit protocols] igmp-snooping { vlan all { immediate-leave; interface <multicast router interface name>.<logical unit> { multicast-router-interface; } } } mld-snooping { vlan all { immediate-leave; interface <multicast router interface name>.<logical unit> { multicast-router-interface; } } } For VLAN-specific values, verify IGMP and MLD snooping is configured for each VLAN: [edit protocols] igmp-snooping { vlan vlan-name { immediate-leave; interface <multicast router interface name>.<logical unit> { multicast-router-interface; } interface <host interface name>.<logical unit> { host-only-interface; } } } mld-snooping { vlan vlan-name { immediate-leave; interface <multicast router interface name>.<logical unit> { multicast-router-interface; } interface <host interface name>.<logical unit> { host-only-interface; } } } If the switch is not configured to implement IGMP or MLD snooping for each VLAN, this is a finding.

Fix Text

Configure IGMP or MLD snooping for IPv4 and IPv6 multicast traffic respectively for each VLAN. Global: set protocols igmp-snooping vlan all immediate-leave set protocols igmp-snooping vlan all interface <multicast router interface name>.<logical unit> multicast-router-interface set protocols mld-snooping vlan all immediate-leave set protocols mld-snooping vlan all interface <multicast router interface name>.<logical unit> multicast-router-interface Per VLAN: set protocols igmp-snooping vlan vlan-name immediate-leave set protocols igmp-snooping vlan vlan-name interface <multicast router interface name>.<logical unit> multicast-router-interface set protocols igmp-snooping vlan vlan-name interface <host interface name>.<logical unit> host-only-interface set protocols mld-snooping vlan vlan-name immediate-leave set protocols mld-snooping vlan vlan-name interface <multicast router interface name>.<logical unit> multicast-router-interface set protocols mld-snooping vlan vlan-name interface <host interface name>.<logical unit> host-only-interface

Additional Identifiers

Rule ID: SV-253963r843922_rule

Vulnerability ID: V-253963

Group Title: SRG-NET-000512-L2S-000002

Expert Comments

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