PIM-DM features

PIM-DM features on switches covered by this guide include:

Routing protocol support

PIM uses whichever unicast routing protocol is running on the routing switch. These can include:

  • RIP

  • OSPF

  • Static routes

  • Directly connected interfaces

VLAN interface support

The MRT supports up to 128 outbound VLANs at any given time. The sum of all outbound VLANs across all current flows on a router may not exceed 128. (A single flow may span one inbound VLAN and up to 128 outbound VLANs, depending on the VLAN memberships of the hosts actively belonging to the flow.)

Flow capacity

Up to 2046 flows are supported in hardware across a maximum of 128 outbound VLANs. (A flow is composed of an IP source address and an IP multicast group address, regardless of the number of active hosts belonging to the multicast group at any given time.)

IGMP compatibility

PIM-DM is compatible with IGMP (V1 to V3) and is fully interoperable with IGMP for determining multicast flows.


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

MIB support

With some exceptions, PIM-DM supports the parts of the multicast routing MIB applicable to PIM-DM operation.

PIM draft specifications

Compatible with PIM-DM draft specifications (V1 and V2.)