How OSPF works explain with example?

How OSPF works explain with example?

OSPF is a routing protocol. Each OSPF router passes along information about the routes and costs they’ve heard about to all of their adjacent OSPF routers, called neighbors. OSPF routers rely on cost to compute the shortest path through the network between themselves and a remote router or network destination.

How do you explain OSPF?

The OSPF (Open Shortest Path First) protocol is one of a family of IP Routing protocols, and is an Interior Gateway Protocol (IGP) for the Internet, used to distribute IP routing information throughout a single Autonomous System (AS) in an IP network.

What is OSPF explain in interview?

The characteristics of OSPF are:

1. OSPF utilize cost as its metric, which is computed based on the bandwidth of the link.
2. OSPF is a classless routing procedure that supports VLSM and CIDR.
3. OSPF routes have an organizational distance of 110.
4. It has no hop-count limit.

How does OSPF determine best path?

If there are multiple routes to a network with the same route type, the OSPF metric calculated as cost based on the bandwidth is used for selecting the best route. The route with the lowest value for cost is chosen as the best route.

Is OSPF hard to learn?

Many students I talk to think they understand OSPF….but they really don’t (for the most part). Not only is OSPF difficult, it’s very complex. Because every router needs to have a complete map of the topology, a lot of rules needs to be followed in order to keep the map sorted to find the best path.

Why we use OSPF?

The idea behind the OSPF areas is to lower the amount of routing traffic and lower the processing of your core routers. Different areas are connected with each other through Area Border Router (ABR). OSPF is link state routing protocol and you can tune a link state routing protocol to converge fast.

What are the characteristics of OSPF?

OSPF supports/provides/advantages –

• Both IPv4 and IPv6 routed protocols.
• Load balancing with equal-cost routes for the same destination.
• VLSM and route summarization.
• Unlimited hop counts.
• Trigger updates for fast convergence.
• A loop-free topology using SPF algorithm.
• Run-on most routers.
• Classless protocol.

What is area in OSPF?

By definition an OSPF area is a collection of networks, not a collection of routers. A backbone network segment is an IP subnet that belongs to the area identified by 0.0. 0.0. Areas that are not physically connected to the backbone are logically connected by a backbone ABR using an OSPF virtual link.

What are the benefits of OSPF?

What are the four OSPF path types?

OSPF Path Selection explained

• Intra-Area (O)
• Inter-Area (O IA)
• External Type 1 (E1)
• NSSA Type 1 (N1)
• External Type 2 (E2)
• NSSA Type 2 (N2)

How do you prioritize OSPF routes?

Setting a Priority for OSPF Routes

1. Run system-view. The system view is displayed.
2. Run ospf [ process-id ] The OSPF process view is displayed.
3. Run preference [ ase ] { preference | route-policy route-policy-name } * A priority is set for OSPF routes. The parameter ase specifies a priority for AS external routes.

What do you need to know about OSPF?

OSPF areas. OSPF uses the concept of areas. An area is a logical grouping of contiguous networks and routers. All routers in the same area have the same topology table, but they don’t know about routers in the other areas. The main benefits of creating areas is that the size of the topology and the routing table on a router is reduced,…

What kind of routing algorithms does OSPF use?

OSPF uses link state routing algorithms and it operates within a single autonomous system. It is a link state open standard-based routing protocol which was created in the 1980s. These days, the protocol can be used by any vendor because it has been made into an open standard.

What does OSPF stand for in IGP protocol?

Open Shortest Path First (OSPF) is one of the Interior Gateway Protocol (IGP), which helps to find the best routing path between the source and the destination router using its own shortest path first (SPF) algorithm.

Why do OSPF routers need to establish neighbor relationships?

Routers running OSPF have to establish neighbor relationships before exchanging routes. Because OSPF is a link state routing protocol, neighbors don’t exchange routing tables. Instead, they exchange information about network topology. Each OSFP router then runs SFP algorithm to calculate the best routes and adds those to the routing table.