A simple routing protocol that uses distance or hop count as its primary metric for determining the best forwarding path. RIP, IGRP and EIGRP are examples. A distance vector protocol routinely sends its neighboring routers copies of its routing tables to keep them up-to-date. Distance vector protocols date back to the ARPAnet network in the early 1970s. Contrast with
link state protocol and
path vector protocol. See
routing protocol.