DISA STIGS Viewer

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 a multicast group only from sources that have been approved by the organization.

Overview

Finding ID Version Rule ID IA Controls Severity
V-272096 CACI-RT-000036 SV-272096r1114286_rule   Medium
Description
Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., someone doing a file download 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
Cisco ACI Router Security Technical Implementation Guide 2025-06-18

Details

Check Text (C-76146r1114107_chk)
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 that it is filtering IGMP or MLD Membership Report messages, allowing hosts to join only those groups that have been approved.

switch BD-1
ip igmp snooping
ip igmp snooping policy ApprovedSources
ip igmp snooping policy ApprovedSources source-filter 10.0.0.1
interface Vlan10
ip igmp snooping policy ApprovedSources

If the Cisco API is not filtering IGMP or MLD Membership Report messages, this is a finding.
Fix Text (F-76053r1114285_fix)
Configure an IGMP snooping policy with source-based filtering, defining which IP addresses are permitted to send multicast traffic to a specific group within a VLAN.

1. Navigate to the relevant interface or bridge domain.

[apic#] switch <bridge-name>
[apic(switch-BD-1)#] ip igmp snooping

2. Within the IGMP Snooping Policy, specify allowed source IP addresses.

[apic(switch-BD-1)#] ip igmp snooping policy<policy-name>
[apic(switch-<bridge-domain-name>)#] ip igmp snooping policy <policy-name> source-filter <source-ip-address1> <source-ip-address2>

3. Assign the created policy to the relevant interface or VLAN.

[apic(switch-BD-1)#] interface <interface-name>
[apic(switch-BD-1)#] ip igmp snooping policy <policy-name>