A protocol used in packet-switched networks by which routers calculate the direction and distance between any two points and route packets based on their calculation of the fewest number of hops. The calculations are based on topology information that each is required to share with neighboring routers when changes occur.Those routers then share the information with their neighbors, and so on, with the updates spreading like ripples in a pond. Distance-vector routing is sometimes referred to as routing by rumor, as most routers depend on hearsay information, rather that on their personal knowledge of network topology. Routing Information Protocol (RIP) is a distance-vector routing protocol.