3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring IPv6 PIM-DM 681
initiates an RPT-to-SPT switchover process upon receiving the first multicast packet
along the RPT by default. The RPT-to-SPT switchover process is as follows:
1 First, the receiver-side DR sends an (S, G) join message hop by hop to the multicast
source S. When the join message reaches the source-side DR, all the routers on the
path have installed the (S, G) entry in their forwarding table, and thus an SPT
branch is established.
2 Subsequently, the receiver-side DR sends a prune message hop by hop to the RP.
Upon receiving this prune message, the RP forwards it towards the IPv6 multicast
source, thus to implement RPT-to-SPT switchover.
After the RPT-to-SPT switchover, IPv6 multicast data can be directly sent from the
source to the receivers. IPv6 PIM-SM builds SPTs through RPT-to-SPT switchover
more economically than IPv6 PIM-DM does through the "flood and prune"
mechanism.
Assert
IPv6 PIM-SM uses exactly the same assert mechanism as IPv6 PIM-DM does. Refer
to
“Assert” on page 674.
Protocols and Standards IPv6 PIM-related specifications are as follows:
■ RFC 2362: Protocol Independent Multicast-sparse Mode(PIM-SM):Protocol
Specification
■ RFC 3973: Protocol Independent Multicast-Dense Mode(PIM-DM):Protocol
Specification(Revised)
■ RFC 3956: Embedding the Rendezvous Point (RP) Address in an IPv6 Multicast
Address
■ draft-ietf-pim-sm-v2-new-06: Protocol Independent Multicast-Sparse Mode
(PIM-SM)
■ draft-ietf-pim-dm-new-v2-02: Protocol Independent Multicast-Dense Mode
(PIM-DM)
■ draft-ietf-pim-v2-dm-03: Protocol Independent Multicast Version 2 Dense
Mode Specification
■ draft-ietf-pim-sm-bsr-02: Bootstrap Router (BSR) Mechanism for PIM Sparse
Mode
■ draft-ietf-ssm-arch-01: Source-Specific Multicast for IP
■ draft-ietf-ssm-overview-04: An Overview of Source-Specific Multicast (SSM)
Configuring IPv6
PIM-DM
IPv6 PIM-DM
Configuration Task List
Complete these tasks to configure IPv6 PIM-DM:
Task Remarks
“Enabling IPv6 PIM-DM” on page 682 Required
“Enabling State Refresh” on page 682 Optional
“Configuring State Refresh Parameters” on page 683 Optional