Bidirectional PIM Redundancy Modes

D.

Bidirectional PIM (PIM-BiDir) is a multicast routing protocol used to support multicast traffic in networks where sources and receivers are sparsely located. Multicast Rendezvous Point (RP) is a key component of PIM-BiDir, used to act as a meeting point for multicast sources and receivers.

In PIM-BiDir, multicast traffic flows in both directions, which makes the RP redundancy important to ensure that multicast traffic continues to flow even if one or more RPs fail. There are four different RP redundancy modes available for PIM-BiDir, including Embedded RP, Phantom RP, MSDP, and PIM Anycast RP.

Embedded RP is a redundancy mode in which each router in the network acts as an RP for a specific group range. The RP information is embedded in the multicast source's packets, and multicast traffic is forwarded to the nearest RP. This mode is easy to deploy and manage, but it can result in high network traffic and poor scalability.

Phantom RP is a redundancy mode in which a virtual RP is created, and the actual RP is hidden behind it. The virtual RP's address is used in multicast packets, and the actual RP's address is hidden. This mode provides better scalability than Embedded RP and reduces the network traffic. However, it requires additional configuration and maintenance to set up the virtual RP.

MSDP (Multicast Source Discovery Protocol) is a protocol used to distribute RP information between different domains or Autonomous Systems (AS). This mode enables multicast traffic to flow between different domains and provides RP redundancy by allowing backup RPs to take over if the primary RP fails. MSDP requires additional configuration and maintenance to set up and can be complex to manage.

PIM Anycast RP is a redundancy mode in which multiple RPs share the same IP address. Multicast traffic is sent to the nearest RP, and backup RPs take over if the primary RP fails. This mode provides good scalability, low network traffic, and easy management. However, it requires additional configuration to set up and can be complex to manage in large networks.

In conclusion, of the four RP redundancy modes available for PIM-BiDir, only Phantom RP, MSDP, and PIM Anycast RP are valid. Embedded RP is not a valid redundancy mode for PIM-BiDir because it does not provide RP redundancy.