Cisco APIC Layer 3 Networking Configuration Guide, Release 6.2(x)

IPv4/IPv6 tenant routed multicast

Updated: April 17, 2026

Want to summarize with AI?

Explains the process to enable or disable IPv4 or IPv6 multicast routing in a Cisco ACI fabric at three hierarchical levels.

IPv4/IPv6 tenant routed multicast is a network routing capability that

enables multicast traffic routing within tenant networks at VRF, L3Out, and bridge domain levels
requires PIM/PIM6 protocol activation for proper multicast distribution, and
operates in a hierarchical configuration model where VRF-level enablement is prerequisite for lower-level activations.

Configuration hierarchy levels

The process to enable or disable IPv4 or IPv6 multicast routing in a Cisco ACI fabric occurs at three levels:

VRF level: Enable multicast routing at the VRF level.
L3Out level: Enable PIM/PIM6 for one or more L3Outs configured in the VRF instance.
Bridge domain level: Enable PIM/PIM6 for one or more bridge domains where multicast routing is needed.

At the top level, IPv4/IPv6 multicast routing must be enabled on the VRF instance that has any multicast routing-enabled bridge domains. On an IPv4/IPv6 multicast routing-enabled VRF instance, there can be a combination of IPv4/IPv6 multicast routing-enabled bridge domains and bridge domains where IPv4/IPv6 multicast routing is disabled. A bridge domain with IPv4/IPv6 multicast routing disabled will not show on the VRF IPv4/IPv6 multicast panel. An L3Out with IPv4/IPv6 multicast routing-enabled will show up on the panel, but any bridge domain that has IPv4/IPv6 multicast routing enabled will always be a part of a VRF instance that has IPv4/IPv6 multicast routing enabled.

IPv4/IPv6 multicast routing is not supported on the leaf switches such as Cisco N93128TX, 9396PX, and 9396TX. All the IPv4/IPv6 multicast routing and any IPv4/IPv6 multicast-enabled VRF instance should be deployed only on the switches with -EX and -FX in their product IDs.

Note

L3Out ports and sub-interfaces are supported. Support for external SVIs varies, depending on the release:

For releases prior to release 5.2(3), external SVIs are not supported.

Beginning with release 5.2(3), support is available for Layer 3 multicast on an SVI L3Out. PIM is supported on SVI L3Outs for physical ports and port channels but not for vPCs. PIM6 is not supported on L3Out SVIs.

Need help?

Open a support case

(Requires a Cisco Service Contract)

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.