Convergence with Link State Protocols

Link State protocols use the Dijkstra Shortest Path First (SPF) algorithm to calculate the best path to each destination network. The SPF algorithm constructs a topology map of the network, and each router calculates the shortest path to every other router in the network based on the link costs. This calculation takes into account both the bandwidth and the delay of each link.

Convergence with Link State protocols is faster than Distance Vector protocols. Link State protocols do not send the entire routing table in every update message like Distance Vector protocols. Instead, they only send updates for changes in the network topology. This reduces the size of the update messages and makes the convergence faster.

When a change occurs in the network topology, Link State protocols send a Link State Advertisement (LSA) to all routers in the network. Routers use the received LSAs to update their topology database and recalculate their routing table. This process is called SPF recalculation, and it results in faster convergence times than Distance Vector protocols. One disadvantage of Link State protocols is that they require more memory and processing power than Distance Vector protocols because they maintain a full topology map of the network. However, this disadvantage is mitigated by the fact that most modern routers have enough memory and processing power to handle Link State protocols efficiently.