OSPF

Définition

OSPF[1] is a link-state protocol that builds a complete map of the network topology, allowing routers to calculate the shortest paths efficiently.

Key characteristics of OSPF[1]:

  • Link-state protocol, each router maintains a map of the network topology

  • Uses costas metric

  • Fast convergence, suitable for medium/large networks

Exemple

OSPF[1] selects the path with the lowest total cost. Each link has a cost (weight).

OSPF illustration

Red path = lowest total cost = 1 + 2 + 1 + 1 = 5 → selected by OSPF[1]

Blue dashed path = total cost = 1 + 2 + 3 + 1 + 1=8 → not selected

OSPF[1] considers link costs instead of just hop count