Exam 400-007 topic 1 question 53 discussion

B: Initially you would think it was A for SSM, but this is only applicable to specific applications. Here, applications are not mentioned, we're talking about building a network. Interdomain is mentioned also which makes me think of MSDP. Technically SSM could support interdomain also. Its a tricky question!!

The correct answer is A. PIM-SSM (Protocol Independent Multicast – Source-Specific Multicast). PIM-SSM is the ideal choice for a multidomain, multicast-based network that forwards traffic using the Shortest Path Tree (SPT). PIM-SSM builds the SPT from the source directly to the receivers, eliminating the need for a Rendezvous Point (RP) and the shared tree

Answer is A: PIM-SSM is specifically designed for IPv6 (as well as IPv4) environments where multicast traffic needs to be delivered from specific sources to specific receivers. PIM-SSM exclusively uses SPTs

I think the key here is multi-domain. I don't know how can you have multi-domain PIM-SSM.

The key use the shared tree SPT to transmit traffic PIM-SSM only use the SPT in the first moment, latter change to SST

PIM-SSM and PIM-DM use only SPT PIM-SM use RPT for first packet and then switch to SPT BIDIR-PIM use only RPT. Answer should be A consider DM is normally not a good idea.

Sparse mode operation centers around a single unidirectional shared tree whose root node is called the rendezvous point (RP). Sources must register with the RP to get their multicast traffic to flow down the shared tree by way of the RP. This registration process actually triggers a shortest path tree (SPT) Join by the RP toward the source when there are active receivers for the group in the network. https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipmulti_pim/configuration/xe-16-5/imc-pim-xe-16-5-book/imc-tech-oview.html

Should be A

It's B https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipmulti_pim/configuration/xe-16-5/imc-pim-xe-16-5-book/imc-tech-oview.html

Should be A. PIM source-specific multicast (SSM) uses a subset of PIM sparse mode and IGMP version 3 (IGMPv3) to allow a client to receive multicast traffic directly from the source. PIM SSM uses the PIM sparse-mode functionality to create an SPT between the receiver and the source, but builds the SPT without the help of an RP. IPv6 multicast provides support for intradomain (not interdomain) multicast routing using PIM sparse mode (PIM-SM). PIM-SM uses unicast routing to provide reverse-path information for multicast tree building, but it is not dependent on any particular unicast routing protocol.

should be B

Answer is B PIM-SM use SPT PIM-SSM use SST