OSPF Features, Advantages, Disadvantages

Routers use routing protocols to learn network routes and build routing tables. Open Shortest Path First is an open standard routing protocol. This tutorial lists the features, advantages, and disadvantages of OSPF.

OSPF is one of the two most popular and widely used routing protocols. The other popular protocol is EIGRP. EIGRP is a bit faster and has a lower AD value than OSPF. The AD value is the trustworthiness of the routing protocol.

The main reason why administrators prefer OSPF over EIGRP is that EIGRP is a Cisco proprietary protocol, whereas OSPF is an open standard protocol. To use EIGRP, they have to use all Cisco routers. This restriction does not apply to OSPF. They can run OSPF on any router. OSPF supports all features of EIGRP.

Features of OSPF

  • It is an open standard routing protocol.
  • It is an interior gateway protocol (IGP).
  • It runs within a single routing domain, such as an autonomous system (AS).
  • It uses a concept called areas to optimize network traffic and simplify administration.
  • It uses the Dijkstra algorithm to compute the shortest route to each destination.
  • It runs over IP protocol but does not use a transport protocol (such as TCP or UDP) to encapsulate its data.
  • It encapsulates its data directly in IP packets with protocol number 89.
  • It uses its own error detection and correction mechanism.
  • It is highly flexible, versatile, and scalable.
  • It offers unlimited hop counts.
  • It supports VLSM/CIDR.
  • It supports multi-vendor deployment.
  • It minimizes routing update traffic.

Advantages of OSPF

  • It is an open standard protocol. It can run on most routers.
  • It uses the SPF algorithm to provide a loop-free topology.
  • It uses both trigger updates and incremental updates to provide fast convergence.
  • It supports VLSM and route summarization for a hierarchical design.
  • It supports both versions of the IP protocol. OSPFv2 supports IPv4 and OSPFv3 supports IPv6.
  • It supports load balancing with equal-cost routes for the same destination.
  • It supports networks of all sizes.

Disadvantages OSPF

  • It needs lots of information to calculate the best route for each destination. To store this information, OSPF consumes more memory than other routing protocols.
  • It runs the SPF algorithm to calculate the best route, which requires extra CPU processing.
  • It is complex to configure and difficult to troubleshoot. Only experienced network administrators can configure it.

ComputerNetworkingNotes CCNA Study Guide OSPF Features, Advantages, Disadvantages