Internet Protocols Questions Medium
The purpose of the Reverse Path Forwarding Information Base (RPFIB) is to prevent IP address spoofing and ensure the proper forwarding of IP packets in a network. RPFIB is used in multicast routing protocols, such as Protocol Independent Multicast (PIM), to determine the correct path for forwarding multicast traffic.
RPFIB maintains a table that stores information about the reverse path for each source IP address. When a multicast packet is received, the RPFIB is consulted to verify if the packet arrived on the expected interface based on the reverse path. If the packet arrives on the expected interface, it is considered valid and forwarded to the appropriate outgoing interfaces. However, if the packet arrives on an unexpected interface, it is likely a spoofed or invalid packet, and it is dropped to prevent potential network attacks or disruptions.
By using RPFIB, network devices can ensure that multicast traffic is forwarded along the correct path, avoiding loops and ensuring efficient delivery to the intended recipients. RPFIB helps maintain the integrity and security of multicast communication by validating the source of the packets and preventing unauthorized or malicious traffic from entering the network.