Link State Routing Protocol and Building it

Link State Routing Protocol (LSRP) is a type of routing protocol that uses a complex algorithm to build and maintain a topology map of the entire network. LSRP builds the topology map using information gathered from other routers and broadcasts, allowing each router to have a complete picture of the network topology.

To build the topology map, LSRP routers use Link State Advertisements (LSAs) to communicate information about the state of the network. Each LSA contains information about the router and the links it is connected to, as well as information about the state of the links and the networks they connect to.

LSRP routers use a Shortest Path First (SPF) algorithm to determine the best path to each destination network in the topology map. The SPF algorithm calculates the shortest path to each network by adding up the costs of each link in the path.

One advantage of LSRP over Distance Vector Routing Protocol is that LSRP uses much less bandwidth because it only sends updates when there is a change in the network topology, rather than sending updates at regular intervals. However, LSRP can be more complex to configure and maintain than Distance Vector Routing Protocol.

To configure LSRP, you need to follow the steps below:

Choose an LSRP protocol to use, such as Open Shortest Path First (OSPF) or Intermediate System to Intermediate System (IS-IS).

Assign a router ID to each router in the network. The router ID is a unique identifier that distinguishes each router in the network.

Configure the LSRP protocol on each router, including the network addresses and areas.

Configure the interfaces on each router, including the IP address and subnet mask.

Verify the LSRP configuration using show commands and by checking the routing table.

Once LSRP is configured, the routers in the network will exchange LSAs to build and maintain a topology map of the network. The SPF algorithm will then determine the best path to each network in the topology map, and the routers will update their routing tables accordingly.