Cisco Cisco IOS Software Release 12.0(22)S

This feature module describes the Bidirectional PIM (bidir-PIM) feature. It includes the following 
sections:

Bidir-PIM is a variant of the Protocol Independent Multicast (PIM) suite of routing protocols for IP 
multicast. In PIM, packet traffic for a multicast group is routed according to the rules of the mode 
configured for that multicast group. The Cisco IOS implementation of PIM supports three modes for a 
multicast group:

Bidirectional mode

Dense mode

Sparse mode

A router can simultaneously support all three modes or any combination of them for different multicast 
groups. In bidirectional mode, traffic is routed only along a bidirectional shared tree that is rooted at the 
rendezvous point (RP) for the group. In bidir-PIM, the IP address of the RP acts as the key to having all 
routers establish a loop-free spanning tree topology rooted in that IP address. This IP address need not 
be a router, but can be any unassigned IP address on a network that is reachable throughout the PIM 
domain. Using this technique is the preferred configuration for establishing a redundant RP 
configuration for bidir-PIM.

12.1(2)T

This feature was introduced.

12.0(18)ST

This feature was integrated into Cisco IOS Release 12.0(18)ST.

12.0(22)S

This feature was integrated into Cisco IOS Release 12.0(22)S.