Link State Routing
Consider the example above. Using the Shortest Path Algorithm (Networking), RIP you can make an adjacency matrix to represent the directed graph.
Who uses this protocol? All other routers on the network.
What does it do: State of its local links
It creates the Link State Datatable (oh boy we love our tables) using Dijkstra's Algorithm, which is this weighted adjacency matrix.
Here's the paths sent to/from the routers after 2 iterations (unweighted path fo 2):
| A | B | C | D | E |
|---|---|---|---|---|
| (A,B,2) | (B,A,1) | (C,A, 4) | (A,B,2) | (E,D,3) |
| (A,C,2) | (B,C, 3) | (C,B,4) | (D,E,3) | |
| (B,D,3) | (C,D, 4) | (D,C,1) |
notation: (source router, dest. router, length (in weight))
Adjacency Matrix:
| Source (below) Dest (Right) | A | B | C | D | E |
|---|---|---|---|---|---|
| A | 2 | 2 | |||
| B | 1 | 3 | 3 | ||
| C | 4 | 4 | 4 | ||
| D | 2 | 1 | 3 | ||
| E | 3 | ||||
| Essentially |
Here:
- this allows for a global view of the network
- routers don't face the count to infinity problem unlike the Shortest Path Algorithm (Networking), RIP#Distance Vector Routing.
- The only real problem is that it is complex (and expensive to do).