Advantages and Disadvantages of Link-State

There are several advantages and disadvantages of link-state routing protocols compared to distance vector routing protocols. In this article, we are going to discuss the advantages and disadvantages of a link-state routing protocol.

Advantages of link-state

  • Fast Network Convergence– Fast network convergence is the main advantage of the link-state routing protocol. Because on receiving an LSP, link-state routing protocols immediately flood the LSP out all interfaces without any changes except for the interface from which the LSP was received.
  • Topological Map– Link-state routing uses a topological map or SPF tree for creating the network topology. Using the SPF tree, each router can separately determine the shortest path to every network.
  • Hierarchical Design– Link-state routing protocols use multiple areas and create a hierarchical design to networks areas. The multiple areas allow better route summarization.
  • Event-driven Updates– After initial flooding of LSPs, the LSPs are sent only when there is a change in the topology and contain only the information regarding that change. The LSP contains only the information about the affected link. The link-state never sends periodic updates.

Disadvantages of Link-State

The Link-state also has some disadvantages compared to distance vector routing protocols:

  • Memory Requirements– the link-state routing protocol create and maintain a database and SPF tree. The database and SPF tree required more memory than a distance vector protocol.
  • Processing Requirements– Link-state routing protocols also require more CPU processing because the SPF algorithm requires more CPU time than distance-vector algorithms just like Bellman-Ford because link-state protocols build a complete map of the topology.
  • Bandwidth Requirements–The link-state routing protocol flood link-state packet during initial startup and also at the event like network break down, and network topology changes, which affect the available bandwidth on a network. If the network is not stable it also creates issues on the bandwidth of the network