Routing: Difference between revisions
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In computer networking, '''routing''' is the process of receiving a [[packet]] on one interface of a [[router]], validating the packet, and, assuming the router knows that a particular outbound interface will move the packet one [[hop]] closer to its final destination, forwards it out that interface. | In computer networking, '''routing''' is the process of receiving a [[packet]] on one interface of a [[router]], validating the packet, and, assuming the router knows that a particular outbound interface will move the packet one [[hop]] closer to its final destination, forwards it out that interface. | ||
Routing is not terribly difficult than driving to a destination along a set of highways. Each exit sign informs the driver of a set of destinations reachable through that exit. The driver will decide to take the exit if it goes toward the destination, or will continue looking for a better exit. | Routing is not terribly more difficult than driving to a destination along a set of highways. Each exit sign informs the driver of a set of destinations reachable through that exit. The driver will decide to take the exit if it goes toward the destination, or will continue looking for a better exit. | ||
The process that draws the "map" of the network, or, in the highway analogy, puts the list of destinations on the exit sign, is the [[control plane]] of the router. The process that actually moves the packet from input to output is the [[forwarding plane]].<ref name=FORCES>{{citation | The process that draws the "map" of the network, or, in the highway analogy, puts the list of destinations on the exit sign, is the [[control plane]] of the router. The process that actually moves the packet from input to output is the [[forwarding plane]].<ref name=FORCES>{{citation | ||
Revision as of 02:00, 15 January 2009
In computer networking, routing is the process of receiving a packet on one interface of a router, validating the packet, and, assuming the router knows that a particular outbound interface will move the packet one hop closer to its final destination, forwards it out that interface.
Routing is not terribly more difficult than driving to a destination along a set of highways. Each exit sign informs the driver of a set of destinations reachable through that exit. The driver will decide to take the exit if it goes toward the destination, or will continue looking for a better exit.
The process that draws the "map" of the network, or, in the highway analogy, puts the list of destinations on the exit sign, is the control plane of the router. The process that actually moves the packet from input to output is the forwarding plane.[1]
The device that performs these functions is called a router.[2] Physically, a router is usually a special-purpose computer, although it is possible to program a personal computer to route.
References
- ↑ Khosravi, H. & T. Anderson (November 2003), Requirements for Separation of IP Control and Forwarding], Internet Engineering Task Force, RFC3654
- ↑ Baker, F. (June 1995), Requirements for IPv4 routers, Internet Engineering Task Force, RFC1812