PIM-DM defaults, protocols, and supported configurations

Default configuration

PIM-DM is disabled by default. Either PIM-SM or PIM-DM can be configured within a VRF at a time. All the interfaces within the VRF must run with same mode.

Routing protocol support

PIM uses unicast routing information from any of the routing protocols that are running on the system, such as OSPFv2, OSPFv3, BGP. Static routes are also supported with Nexthop IP addresses.

PIM enabled interfaces (L3 and SVI)

PIM can be enabled across all VRFs on a maximum of 1,000 interfaces with an upper limit of 128 per VRF.


Although up to 128 PIM DM enabled interfaces can be configured, when configuring trunk interfaces with multiple Dense enabled SVIs, the trunk interfaces must have sufficient bandwidth or have only the required number of trunks it can support. This ensures that the link utilization is not exceeded due to the initial flooding nature of the protocol.

IGMP and MLD compatibility

PIM-DM is compatible with IGMP version 2 and version 3, MLD version 1 and version 2, and is fully interoperable with IGMP/MLD for determining multicast flows.


PIM-DM is fully interoperable with VRRP to quickly transition multicast routes in a failover.

VRF support

PIM-DM can run on multiple VRF instances in parallel. It is supported on all VRFs supported in the system.

PIM-DM currently does not support the following:

  • VxLAN, 6in4, 6in6, and GRE interfaces

  • PIM-DM can be enabled on VSX deployments, however active-active functionality is not available.


    Since active-active is not supported a slightly higher traffic recovery time can be expected compared to sparse mode, in the event of failovers. Hence, it is recommended to use PIM-SM on VSX.

    Ensure that the ISL is not oversubscribed while using PIM-DM with VSX. In case of numerous PIM enabled SVIs, ensure that ISL is configured to handle the flooding on all VLANs since ISL is member of all SVIs.