Anycast Rp; Implementation Information; Configure Multicast Source Discovery Protocol - Dell S4048–ON Configuration Manual

Figure 86. MSDP SA Message Format

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.

Implementation Information

The Dell Networking OS implementation of MSDP is in accordance with RFC 3618 and Anycast RP is in accordance with RFC 3446.

Configure Multicast Source Discovery Protocol

Configuring MSDP is a four-step process.
1. Enable an exterior gateway protocol (EGP) with at least two routing domains.
Refer to the following figures.
The MSDP Sample Configurations
Shortest Path First (OSPFv2)
2. Configure PIM-SM within each EGP routing domain.
Refer to the following figures.
The MSDP Sample Configurations
(PIM-SM).
520
Multicast Source Discovery Protocol (MSDP)
show the OSPF-BGP configuration used in this chapter for MSDP. Also, refer to
and Border Gateway Protocol IPv4
show the PIM-SM configuration in this chapter for MSDP. Also, refer to
(BGPv4).
Open
PIM Sparse-Mode