Multicast Source Discovery Protocol; Rpf Policies In An Extranet - Cisco XR 12000 Series Configuration Manual

Implementing Multicast Routing on Cisco IOS XR Software Cisco ASR 9000 Series Routers
Figure 8
Source
For more information, see also
MVPN Extranet Routing: Example, page

RPF Policies in an Extranet

RPF policies can be configured in receiver VRFs to bypass RPF lookup in receiver VRFs and statically
propagate join states to specified source VRF. Such policies can be configured to pick a source VRF
based on either multicast group range, multicast source range, or RP address.
For more information about configuration of RFP policies in extranets, see
Receiver VRFs to Propagate Joins to a Source VRF: Example, page MCC-93
Policies in Receiver VRFs on Source PE Routers to Propagate Joins to a Source VRF: Example,
page

Multicast Source Discovery Protocol

Multicast Source Discovery Protocol (MSDP) is a mechanism to connect multiple PIM sparse-mode
domains. MSDP allows multicast sources for a group to be known to all rendezvous points (RPs) in
different domains. Each PIM-SM domain uses its own RPs and need not depend on RPs in other
domains.
An RP in a PIM-SM domain has MSDP peering relationships with MSDP-enabled routers in other
domains. Each peering relationship occurs over a TCP connection, which is maintained by the
underlying routing system.
MSDP speakers exchange messages called Source Active (SA) messages. When an RP learns about a
local active source, typically through a PIM register message, the MSDP process encapsulates the
register in an SA message and forwards the information to its peers. The message contains the source
and group information for the multicast flow, as well as any encapsulated data. If a neighboring RP has
local joiners for the multicast group, the RP installs the S, G route, forwards the encapsulated data
contained in the SA message, and sends PIM joins back towards the source. This process describes how
a multicast path can be built between domains.
OL-
Receiver MVRF at the Source PE Router Receiver
Packets received in MVRF for
VPN-A from the source
MVRF for VPN-A
MVRF for VPN-B
CE
VPN-A
MCC-96.
Packets are independently
replicated and encapsulated in
the MVRF for VPN-A and
VPN-B
MVRF for VPN-B
PE1 P
MVRF for VPN-A
Configuring MVPN Extranet Routing, page MCC-52
MCC-91.
Information About Implementing Multicast Routing
PE2 and PE3 decapsulate and
forward the packets to the
respective MVRFs
VPN-B
CE
PE2
PE3
CE
VPN-A
and
Configuring RPL Policies in
and Configuring RPL
Multicast Configuration Guide
Receiver
Receiver
Configuring
MCC-19