Distance-Vector Routing
Distance-vector routing makes this assumption:
Each router knows the identity of every other router in the network.
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In an attempt to enforce this assumption, each router will maintain a
distance vector, comprised of the list of tuples:
< destination, cost >
... for all nodes in the network. Here, cost is the
current estimate of the shortest path from this
router to the destination; the estimate is never
smaller than the real cost of the path.
The distance-vector algorithm is a distributed implementation of the
Bellman-Ford algorithm:
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Each router periodically sends a copy of its distance vector to its neighbors.
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When a router receives a distance vector from a neighbor, it determines
whether its cost of reaching any destination would decrease if packets
to that destination were to be sent through that neighbor.
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If so, that router updates its own distance vector.
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