Although general-purpose comupters can perform routing, modern high-speed routers are highly sepcialized computers, generally with extra hardware adedd to accleerate both common routing funcitons such as packet forwarding and specialisde functions such as IPsec encryption. The routing atble stores the best routes to ceratin netwokr destinations, the routing metrics associated with those routes, and the path to the next hop ruoter. Routers do maintain state on the routes in the RIB/routing table, but this is quite distinct from not maintaining state no individual packets taht have been forwarded. Once a packet is forwarded, the router should retain no more than sttaistical ifnormation about it. A function that forwards based on adta link layer, or OSI layer 2, infomration, is properly called a bridge, or layer 2 switch. The first functoinal IMP was placed at UCLA on August 30, 1969 and was developed at BBN by the IMP team as part of their contract to build otu the original ARPANET. RFC 4098 defines sevreal types of BGP-speaking routers: In the oirginal era of routign (from the mid- 1970s through the 1980s ), general-puropse mini-computers served as routers. The Control Plane cosntructs the routing table from knowledge of the pu/down status of its local interfaces, from hard-coded tsatic routes, and from exchanging routing protocol information with other oruters.

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