Explain the difference between forwarding and routing processes. Include in your explanation comments on how the two interact.-DPDK中文网

Forwarding and routing are two essential processes in the delivery of data packets across a network. While these terms are often used interchangeably, they represent distinct functions that work together to ensure efficient communication between devices.

Routing is the process of determining the best path for data packets to travel from their source to their destination. The goal of routing is to find the shortest, fastest, or most reliable route possible while taking into account network congestion, link quality, and other factors that may affect packet delivery. Routers use algorithms like OSPF (Open Shortest Path First) or BGP (Border Gateway Protocol) to make routing decisions based on information gathered from other routers.

Forwarding, on the other hand, refers to the actual transmission of data packets from one device to another along a specific path determined by the routing process. Forwarding is performed by routers or switches located at each hop along the route between the source and destination devices. These devices inspect each incoming packet’s destination address and forward it out through the appropriate interface towards its next hop until it reaches its final destination.

The interaction between forwarding and routing processes is as follows:

A packet arrives at a router’s input port.
The router uses its routing table to determine which output port should be used for this packet.
The router then forwards the packet out through that output port towards its next hop.
This process repeats at each subsequent router along the path until it reaches its final destination.

In summary, Routing decides which path packets should take through a network while forwarding performs actual transmission of those packets over individual links along that path determined by routing.