OSPF Process Explained | Significance of multiple OSPF processes

This video explains what OSPF processes are and when to run multiple OSPF processes on the same router.
[Video Transcript]
OSPF process
OSPF allows you to run multiple instances on the same router. Each instance is called a process. Every process is unique and does not share routing information with other processes running on the same router. A process is locally significant. You can use the same process ID on the different routers. However, you can not use the same process ID to run two processes on the same router.

Significance of multiple OSPF processes
Running multiple OSPF processes on the same router provides no benefit if you want it to share all routing information with other OSPF routers. It is beneficial only when you want the router to share specific routing information with other OSPF routers.
Let us take an example.
In this network, OSPF is running on these routers. You want to configure OSPF on this router. How you will configure OSPF on this router depends on how you want this network to function. If you want this network to work as a single network, configure only one OSPF process on this router and advertise all routes in that process.
If you want to divide it into two separate networks, configure two OSPF processes and advertise only relative routes in each process. If you use this configuration, routers running in Network One will not learn about the routes and routers available in Network Two. Similarly, routers in Network Two will never be aware of the routes and routers available in Network One. However, this router knows routes and routers available in both networks. This configuration allows the router to connect to different OSPF networks without mixing their routing information. You can use it in a situation where you want to connect multiple OSPF networks separately using a single router.
OSPF process key points:-
OSPF processes are locally significant.
You can use the same process ID on the different routers.
You can not use the same process ID to run two processes on the same router.
Each OSPF process runs as an individual OSPF instance.
Each OSPF process maintains separate routing information. It does not share its routing information with the OSPF process running on the same router.
Running multiple OSPF processes on the same router is beneficial only when you want it to connect to other OSPF routers separately.
If you want to share all routing information, use a single OSPF process. It will make OSPF configuration straightforward.

Видео OSPF Process Explained | Significance of multiple OSPF processes канала ComputerNetworkingNotes