When implementing interdomain multicast routing, which mechanism can be used to advertise multicast sources in one domain to the other domains, allowing the RPs to build interdomain multicast distribution trees?
A . Multiprotocol BGP
B . PIM
C . MSDP
D . Auto RP
E . BSR
F . MLD
Answer: C
Explanation:
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 point(s) (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 routingsystem.
MSDP speakers exchange messages called Source Active (SA) messages. When an RP learns about a localactive source, typically through a PIM register message, the MSDP process encapsulates the register in an SAmessage and forwards the information to its peers. The message contains the source and group informationfor the multicast flow, as well as any encapsulated data. If a neighboring RP has local joiners for the multicastgroup, the RP installs the S, G route, forwards the encapsulated data contained in the SA message, and sendsPIM joins back towards the source. This process describes how a multicast path can be built betweendomains.