Install Guide

Table Of Contents
Figure 83. MSDP SA Message Format
Topics:
Anycast RP
Implementation Information
Configure Multicast Source Discovery Protocol
Enable MSDP
Manage the Source-Active Cache
Accept Source-Active Messages that Fail the RFP Check
Specifying Source-Active Messages
Limiting the Source-Active Messages from a Peer
Preventing MSDP from Caching a Local Source
Preventing MSDP from Caching a Remote Source
Preventing MSDP from Advertising a Local Source
Logging Changes in Peership States
Terminating a Peership
Clearing Peer Statistics
Debugging MSDP
MSDP with Anycast RP
Configuring Anycast RP
MSDP Sample Configurations
Anycast RP
Using MSDP, anycast RP provides load sharing and redundancy in PIM-SM networks. Anycast RP allows two or more
rendezvous points (RPs) to share the load for source registration and the ability to act as hot backup routers for each other.
Anycast RP allows you to configure two or more RPs with the same IP address on Loopback interfaces. The Anycast RP
Loopback address are configured with a 32-bit mask, making it a host address. All downstream routers are configured to know
that the Anycast RP Loopback address is the IP address of their local RP. IP routing automatically selects the closest RP
for each source and receiver. Assuming that the sources are evenly spaced around the network, an equal number of sources
register with each RP. Consequently, all the RPs in the network share the process of registering the sources equally. Because
a source may register with one RP and receivers may join to a different RP, a method is needed for the RPs to exchange
information about active sources. This information exchange is done with MSDP.
With Anycast RP, all the RPs are configured to be MSDP peers of each other. When a source registers with one RP, an SA
message is sent to the other RPs informing them that there is an active source for a particular multicast group. The result is
that each RP is aware of the active sources in the area of the other RPs. If any of the RPs fail, IP routing converges and one of
the RPs becomes the active RP in more than one area. New sources register with the backup RP. Receivers join toward the new
RP and connectivity is maintained.
Multicast Source Discovery Protocol (MSDP)
517