IP PIM Sparse Mode

IP PIM Sparse Mode
Sparse mode was developed to use shared root source tree distribution and relies on the knowledge
of an RP. If an RP cannot be found, the router is unable to forward multicast information,
TABLE 1 9 . 2 IP PIM Configuration Options
IP PIM Options Description
bsr-border Specifies the border of the PIM domain.
dense-mode Enables PIM dense-mode operation.
nbma-mode Specifies the use of non-broadcast multi-access (NBMA) mode on
the interface.
neighbor-filter Specifies the PIM peering filter.
query-interval Specifies the PIM router query interval.
sparse-dense-mode Enables PIM sparse-dense-mode operation.
sparse-mode Enables PIM sparse-mode operation.
version Displays the PIM version.
624 Chapter 19  Understanding and Configuring Multicast Operation
strictly because it does not know the source of the multicast traffic. If it can’t determine where the
traffic is supposed to be coming from, the Reverse Path Forwarding (RPF) check fails and no interfaces
are added to the multicast forwarding table.
Configuration of PIM sparse mode is just as simple as it is for IP dense mode. The command
for enabling IP PIM sparse mode is ip pim sparse-mode. Sparse mode PIM also activates
IGMP on the interface, allowing the interface to listen for IGMP membership reports. Here is
an example of enabling IP PIM sparse mode multicast on an interface:
Terry_3640#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Terry_3640(config)#interface FastEthernet3/0
Terry_3640(config-if)#ip pim sparse-mode
Terry_3640(config-if)#^Z
Terry_3640#
Here is a look at the interface configuration after the preceding execution:
!
interface FastEthernet3/0
ip address 172.16.21.4 255.255.255.0
no ip directed-broadcast
ip pim sparse-mode
!
All forms of sparse mode also require a rendezvous point to be configured.