PIM-SM features

PIM-SM on the switches covered in this guide include:

Routing protocol support
PIM uses whichever IP unicast routing protocol is running on the router. These can include:
  • RIP

  • OSPF

  • Static routes

  • Directly connected interfaces

VLAN interface support:

Up to 127 outbound VLANs (and 1 inbound VLAN) are supported in the multicast routing table (MRT) at any given time. This means the sum of all outbound VLANs across all current flows on a router may not exceed 127. (A single flow may span one inbound VLAN and up to 127 outbound VLANs, depending on the VLAN memberships of the hosts actively belonging to the flow.) For 2930F switch, 16 VLANs are supported.

Flow capacity:

Up to 2046 flows are supported in hardware across a maximum of 128 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.)

Multicast group to RP mapping:

PIM-SM uses the BSR protocol to automatically resolve multicast group addresses to C-RP routers. In the current software release, a router administers BSR operation on a PIM-SM domain basis. (BSR zones and PIM border router operation are not currently supported by the switches covered in this guide.) Note that BSR operation does not extend to statically configured RPs.

IGMP compatibility:

PIM-SM is compatible with IGMP version 2, and is fully interoperable with IGMP for determining multicast flows.


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

MIB support on the switches covered in this guide:

PIM-SM supports the Protocol Independent Multicast MIB for IPv4 (RFC 2934.)

With some exceptions, PIM-SM supports the parts of the multicast routing MIB (RFC 2932) applicable to PIM-SM operation.

PIM draft specifications:

Compatible with PIM-SM specification ( RFC 4061.)

BSR implementation:

Complies with RFC 5059 (scope zones are not supported.)

Maximum number of routes:

For the 2930F switch, the maximum number of routes is limited to 200.