OSPF Fundamental Terminology

OSPF stands for Open Shortest Path First. OSPF is a link state open standard based routing protocol. It was created in mid-1980. Since it is based on open standard, we can use it with any vendor’s router.

Features and advantage of OSPF

·    It supports both IPv4 and IPv6 routed protocols.

·    It supports load balancing with equal cost routes for same destination.

·    Since it is based on open standards, it will run on most routers.

·    It provides a loop free topology using SPF algorithm.

·    It is a classless protocol.

·    It supports VLSM and route summarization.

·    It supports unlimited hop counts.

·    It scales enterprise size network easily with area concept.

·    It supports trigger updates for fast convergence.

Just like other routing protocols, OSPF also has its negatives.

Disadvantage of OSPF

·    It requires extra CPU process to run SPF algorithm.

·    It requires more RAM to store adjacency topology.

·    It is more complex to setup and hard to troubleshoot.

Basically OPSF was created to fulfill the requirement of enterprise size network. To scale a large size network it uses area concept. Area concept is similar to Subnetting. It allows us to separate the large internetwork into smaller networks known as areas.

Along with Area concept OSPF also supports Autonomous System (AS). Just like area, AS also divide a large network into smaller networks.