The Cisco ACI multicast must be configured to filter the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Report messages to allow hosts to join only multicast groups and only from sources that have been approved by the organization.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
low	V-272095	SRG-NET-000364-RTR-000114	CACI-RT-000035	SV-272095r1168413_rule	2025-12-11	1

Description
Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., occasional file downloads), 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. Satisfies: SRG-NET-000364-RTR-000115

Description

Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., occasional file downloads), 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. Satisfies: SRG-NET-000364-RTR-000115

ℹ️ Check
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 switch. Review the configuration to verify filtering IGMP or MLD Membership Report messages, allowing hosts to join only those groups that have been approved. Navigate to the following location to review the settings: Tenants >> {{your_Tenant}} >> Networking >> Bridge Domain >> {{your_Bridge_Domain}} >> Policy >> General If the Cisco ACI is not filtering IGMP or MLD Membership Report messages, this is a finding.

ℹ️ Check

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 switch. Review the configuration to verify filtering IGMP or MLD Membership Report messages, allowing hosts to join only those groups that have been approved. Navigate to the following location to review the settings: Tenants >> {{your_Tenant}} >> Networking >> Bridge Domain >> {{your_Bridge_Domain}} >> Policy >> General If the Cisco ACI is not filtering IGMP or MLD Membership Report messages, this is a finding.

✔️ Fix
Configure IGMP Snooping. Note: There are a number of methods for meeting this requirement; however, it is recommended to use filter Destinations via contracts and PIM destination filter route maps when enabling the Bridge domain to participate in IGMP and MLD Snooping. All but the contract settings can be found at the following GUI path: Tenants >> {{your_Tenant}} >> Networking >> Bridge Domain >> {{your_Bridge_Domain}} >> Policy >> General

✔️ Fix

Configure IGMP Snooping. Note: There are a number of methods for meeting this requirement; however, it is recommended to use filter Destinations via contracts and PIM destination filter route maps when enabling the Bridge domain to participate in IGMP and MLD Snooping. All but the contract settings can be found at the following GUI path: Tenants >> {{your_Tenant}} >> Networking >> Bridge Domain >> {{your_Bridge_Domain}} >> Policy >> General