Which statement is correct regarding MP-BGP?

Which statement is correct regarding MP-BGP?
A . MP-BGP can indicate whether an advertised prefix (NLRI) is to be used for unicast routing, multicast RPF checks or for both using different SAFIs.
B . MP-BGP uses a single BGP table to maintain all the unicast prefixes for unicast forwarding and all the unicast prefixes for RPF checks.
C . MP-BGP can be used to propagate multicast state information, which eliminates the need to use PIM for building the multicast distribution trees.
D . MP-BGP enables BGP to carry IP multicast routes used by MSDP to build the multicast distribution trees.

View Answer

Answer: A

Explanation:

Protocol Independent Multicast

Protocol Independent Multicast (PIM) is a routing protocol designed to send and receive multicast routingupdates. Proper operation of multicast depends on knowing the unicast paths towards a source or an RP. PIMrelies on unicast routing protocols to derive this reverse-path forwarding (RPF) information. As the name PIMimplies, it functions independently of the unicast protocols being used. PIM relies on the Routing Information Base (RIB) for RPF information. If the multicast subsequent address family identifier (SAFI) is configured for Border Gateway Protocol (BGP), or if multicast intact is configured, a separate multicast unicast RIB is createdand populated with the BGP multicast SAFI routes, the intact information, and any IGP information in theunicast RIB. Otherwise, PIM gets information directly from the unicast SAFI RIB. Both multicast unicast andunicast databases are outside of the scope of PIM.

The Cisco IOS XR implementation of PIM is based on RFC 4601 Protocol Independent Multicast – Sparse

Mode (PIM-SM): Protocol Specification. For more information, see RFC 4601 and the Protocol

Independent Multicast (PIM): Motivation and Architecture Internet Engineering Task Force (IETF) Internet draft