OSPF stands for open shortest path first, it is the link state dynamic routing protocol which is used for routing with in Autonomous system. That is, OSPF is interior gateway protocol (IGP) . OSPF is based on OPEN Standard such that it is supported by all router vendors.

While it’s predecessor RIP is distance vector protocol, OSPF is the link state routing protocol

Advantages
OSPF Supports both IPv4 and IPv6
OSPF has support for classless address routing
It supports VLSM(variable length subnet mask)
OSPF supports the route summarisation
Unlike it’s predecessor RIP protocol, OSPF supports unlimited hops
Choice of OSPF protocol for hierarchical network topology compliments
OSFP uses the concept of areas, where autonomous system is divided into different regions. Such that routing information between regions is adopted making the reduction of information exchanged greatly even as network scales
It is possible to scale the network to enterprise grade by making use of the concept called areas
OSPF provides the fast convergence: Such that, route changes are transmitted and communicated to the whole autonomous system with in short time span
Using SFP (shortest path first), OSPF
OSPF is virtually supported by all types of routers and all vendors
OSPF offers load balancing with equal cost routes for the desired destination
OSPF best servers the needs of enterprise networks
OSPF uses the concept of areas, which makes it possible to separate large internetwork into smaller networks called areas
OSPF provides the better security supporting interface based md5 & plaintext authentication
OSPF supports the concept of both Autonomous System(AS)[RFC1771] and area
OSPF is Loop Free
OSPF uses the multicast addresses in broadcast networks such that reducing the interferences to other network devices that do not operate on OSFP

Following are the disadvantages of OSPF protocol

• OSPF costs more CPU and RAM for SPF algorithm and storage of adjacency topologies respectively
• It is complex than RIP protocol

Glossary

AS (Autonomous System) – is the group of networks under a single administrative control

IGP – Interior Gateway Protocol

Multicast – Group of computers or network devices listen on multicast address. A packet sent to multicast address is received by all network devices that are added to that multicast group by that corresponding multicast address