Interdomain Multicast; Ssm; Msdp; Mbgp - Cisco Nexus 7000 Series Configuration Manual

Interdomain Multicast

Interdomain Multicast
Cisco NX-OS provides several methods that allow multicast traffic to flow between PIM domains.

SSM

The PIM software uses SSM to construct a shortest path tree from the designated router for the receiver to a
known source IP address, which may be in another PIM domain. The ASM and Bidir modes cannot access
sources from another PIM domain without the use of another protocol.
Once you enable PIM or PIM6 in your networks, you can use SSM to reach any multicast source that has an
IP address known to the designated router for the receiver.

MSDP

Multicast Source Discovery Protocol (MSDP) is a multicast routing protocol that is used with PIM to support
the discovery of multicast sources in different PIM domains.
Note Cisco NX-OS supports the PIM Anycast-RP, which does not require MSDP configuration.

MBGP

Multiprotocol BGP (MBGP) defines extensions to BGP4 that enable routers to carry multicast routing
information. PIM and PIM6 can use this multicast information to reach sources in external BGP autonomous
systems.
For information about MBGP, see the Cisco Nexus 7000 Series NX-OS Unicast Routing Command Reference.

MRIB and M6RIB

The Cisco NX-OS IPv4 Multicast Routing Information Base (MRIB) is a repository for route information
that is generated by multicast protocols such as PIM and IGMP. The MRIB does not affect the route information
itself. The MRIB maintains independent route information for each virtual routing and forwarding (VRF)
instance in a virtual device context (VDC). For more information about VDCs, see the Cisco Nexus 7000
Series NX-OS Virtual Device Context Configuration Guide.
Similar to the MRIB for IPv4 routing information, the M6RIB maintains IPv6 routing information that is
generated by protocols such as PIM6 and MLD.
This figure shows the major components of the Cisco NX-OS multicast software architecture:
• The Multicast FIB (MFIB and M6FIB) Distribution (MFDM) API defines an interface between the
• The multicast FIB distribution process distributes the multicast update messages to all the relevant
• The Layer 2 multicast client process sets up the Layer 2 multicast hardware forwarding path. It runs on
Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide
12
multicast Layer 2 and Layer 3 control plane modules, including the MRIB and M6RIB, and the platform
forwarding plane. The control plane modules send the Layer 3 route update and Layer 2 lookup information
using the MFDM API.
modules and the standby supervisor. It runs only on the supervisor.
both the supervisor and the modules.
Overview