OSPF

Hi everyone, on today we are going to learn about OSPF lets see in simplified points to understand for cert exams preparation.

In simplified points to remember, Open Shortest Path First (OSPF) 

• It is a link state routing protocol (LSRP) that uses the Shortest Path First (SPF) network communication algorithm (Dijkstra's algorithm) to calculate the shortest connection path between known devices.
• It is an Interior Gateway Protocol (IGP) that routes Internet Protocol (IP) packets within a single routing network domain only. 
• It finds the best network layout (topology) by calculating shortest device connection paths using the Shortest Path First (SPF) algorithm.

For Example: A person in this Metro city A wants to travel to city D and is given two options:

• Travels through cities B and C : The route would be ABCD. And the distance (or bandwidth cost in the networking case) for A-B is 10 miles / Km, B-C is 5 miles /  Km and C-D is 10 miles /  Km.
• Travel through city F : The route would be AFD. And the distance for A-F is 20 miles / Km and F-D is 10 miles / Km. (in Kilometres)

The shortest route is always the one with least amount of distance covered in total. 

Thus, the ABCM route is the better option (10+5+10=25), even though the person has to travel to two cities as the associated total cost to travel to the destination is less than the second option with a single city (20+10=30). 

OSPF performs a similar algorithm by first calculating the shortest path between the source and destination based on link bandwidth cost and then allows the network to send and receive IP packets via the shortest route.

Stay tuned for more information to be shared through this blog and also text at our comment section below.