Huawei Quidway S9300

5.1 Introduction to MSDP
This section describes the basic information about MSDP.
In PIM-SM mode, a multicast source is registered only on the RP in the local domain and the
multicast data transmitted by sources in different domains is separated from each other.
Therefore, the RP obtains only the local source. It establishes the multicast distribution tree only
in the local domain and distributes the data sent by the local source to local users.
If a mechanism can be used to transmit the information from sources in other domains to the
local RP, the local RP can send Join messages to the sources in other domains and establish a
multicast distribution tree. Therefore, multicast data can be transmitted across domains. The
local member hosts can receive the data sent by the sources in other domains.
The Multicast Source Discovery Protocol (MSDP) can solve the preceding problems. It is an
inter-domain multicast solution based on the interconnection among multiple PIM-SM domains.
RPs in PIM-SM domains set up MSDP peer relations. By sending Source Active messages, the
MSDP peers send the (S, G) information from the RP on which source S registers to other RPs
that members of group G join. This is the implementation process of MSDP.
MSDP peers are connected through TCP and they perform RPF check on received SA messages.
NOTE
MSDP is applicable only to PIM-SM domains and is valid only for the ASM model.
5.2 MSDP Features Supported by the S9300
This section describes MSDP features supported by the S9300.
PIM-SM Inter-Domain Multicast
When a multicast network is divided into multiple PIM-SM domains, RPs in all domains
communicate with each other and share information from multicast sources with each other
through MSDP. As a result, the users in a domain can receive multicast data from multicast
sources in other domains.
You can configure MSDP peers in an AS domain, MSDP peers between AS domains, and static
RPF peers.
Anycast RP in a PIM-SM Domain
If you configure the anycast RP in a PIM-SM domain, a multicast source registers to the nearest
RP and the receiver joins the nearest RP. By configuring anycast RP in a PIM-SM domain, you
can:
l Reduce the load of a single RP.
l Realize backup between RPs.
l Optimize the forwarding path.
A loopback interface can function as a C-RP or static RP to specify the logical RP address for
SA messages.
5 MSDP Configuration
Quidway S9300 Terabit Routing Switch
Configuration Guide - Multicast
5-2 Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Issue 01 (2009-07-28)