Routing OSPF (Open Shortest Path First)

Open Shortest Path First (OSPF) is a link-state routing protocol, rather than a distance vector protocol. The main difference here is that a linked-state protocol does not send its routing table in the form of updates, but only shared its connectivity configuration. By collecting connectivity information from all of the devices on the network, OSPF can store all this information in a database and use that information to build a topology map.

This information will allow OSPF to identify the best or shortest route to every other network segment on the network. The route selection is based on overall hops to the destination, as well as link speed or link cost.

The topology not only includes the best route to the destination as calculated by the Dijkstra algorithm (a search algorithm created by Edsger Dijkstra), but also, when possible, it includes a candidate or backup route to the destination.

After creating the topology map, OSPF populates the routing table with the chosen routes to each destination. As traffic passes from router to router, each router evaluates the best path to the destination network. In some cases, this process can lead to routing loops on the network, because each one is evaluating the path based on its own link state database.

Case OSPF Routing:

1. Create Network Topology like below:

Router Solok to Router Padang (172.18.27.0/30)

Router Solok to Router Bukit Tinggi (172.30.22.0/30)

Router Solok to Router Payakumbuh (172.29.24.0/30)

Router Solok to Router Sawahlunto (172.20.28.0/30)

Router Padang to Router Bukit Tinggi (172.16.21.0/30)

Router Bukti Tinggi to Router Payakumbuh (172.19.26.0/30)

Router Payakumbuh to Router Sawahlunto (172.25.14.0/30)

Router Padang to LAN (192.168.1.10/29)

Router Bukit Tinggi to LAN (10.10.23.0/29)

Router Payakumbuh to LAN (192.168.100.0/29)

Router Sawahlunto to LAN (192.168.12.0/29)

I assume you are able to configure the IP address for each router and PC. Next live perform in every Router OSPF Routing.

Router Bukit Tinggi

router ospf 150

network 172.16.21.0 0.0.0.3 area 0

network 172.19.26.0 0.0.0.3 area 1

network 172.30.22.0 0.0.0.3 area 1

Router Padang

router ospf 150

network 172.16.21.0 0.0.0.3 area 0

network 172.18.27.0 0.0.0.3 area 0

Router Payakumbuh

router ospf 150

network 172.25.14.0 0.0.0.3 area 0

network 172.19.26.0 0.0.0.3 area 1

network 172.29.24.0 0.0.0.3 area 1

Router Sawahlunto

router ospf 150

network 172.20.28.0 0.0.0.3 area 0

network 172.25.14.0 0.0.0.3 area 0

Router Solok

router ospf 150

network 172.18.27.0 0.0.0.3 area 0

network 172.20.28.0 0.0.0.3 area 0

network 172.30.22.0 0.0.0.3 area 1

network 172.29.24.0 0.0.0.3 area 1