Open shortest path first ospf operating inside a distinct autonomous system. Link state routing protocols advertise the state of their links. May 19, 2018 introduction to open shortest path first ospf a tutorial open shortest path first ospf is a link state routing protocol which was first defined as version 2 in rfc 2328. It can also be called an act of approach to a state where all routing tables have detailed information are in steadystate. This is a linkstate algorithm protocol compared with distancevector protocols like rip and is categorized as an interior gateway protocol igp like eigrp, isis etc igp protocols are running within the same autonomous system network i. Open shortest path first ospf is an interior gateway protocol igp standardized by the internet engineering task force ietf and commonly used in large enterprise networks. How to configure ospf routing protocol using cisco packet. Routing protocol packets share a common protocol header routing protocol packets are sent with type of service tos of 0 five types of ospf routing protocol packets hello packet type 1 database description packet type 2 linkstate request packet type 3 linkstate update packet type 4 linkstate acknowledgement packet type 5. The router ospf command enables ospf routing on the router, and the 1 before osfp is the process id of the osfp protocol. Ospf stands for open shortest path first and is a routing protocol adaptive for ip networks. Routing information protocol rip routing information protocol rip is a standardized distance vector protocol, designed for use on smaller networks. Introduction to open shortest path first ospf protocol. They take different approaches to share routing updates.
Ospf adheres to the following link state characteristics. Rip routing information protocol is one of the oldest routing protocols still in service. Open shortest path first ospf is a link state routing protocol which was first defined as version 2 in rfc 2328. We begin here a discussion of the terminology of ospf open shortest path first. Like all linkstate protocols, ospf is very efficient in its use of network. The open shortest path first ospf protocol, defined in rfc 2328, is an interior gateway protocol used to distribute routing information within a single autonomous system.
Ospf will form neighbor relationships with adjacent routers in the same area. The open shortest path first ospf protocol, defined in rfc 2328, is an. Open shortest path first ospf is a linkstate routing protocol, rather than a distance vector protocol. We start with a description of only a few terms and proceed to more explanations on subsequent pages. By collecting connectivity information from all of the devices on the network, ospf. Ospf is a linkstate routing protocol providing fast convergence and excellent scalability. Unlike ospf, which was developed and standardized by the internet engineering task force ietf. This paper examines how ospf works and how it can be used to design and build large and complicated networks. This tutorial explains how to configure ospf routing protocol step by step with practical example in packet tracer. Sanctioned by the ietf, it is intended to become internets preferred interior routing protocol. Ospf basics and features link state routing protocol fast convergence basic ospf operation ospf neighbor discovery process ospf packet types and format ospf network topology. Isis is a linkstate interior gateway routing protocol. Open shortest path first ospf is a recent entry into the internet interior routing scene. Its newest implementation, version 2, which is explained in rfc 2328, is an open standard.
The main difference here is that a linkedstate protocol does not send its routing table in the form of updates, but only shared its connectivity configuration. Ospf routes packets based entirely on the destination ip of the. Two routers speaking ospf to each other exchange information about the routes they know about and the cost for them to get there. Teaches good routing protocol design practices isis relaxed two level design l2 routers must be linked through the backbone suits isps with stringy networks, diverse infrastructure, etc, not fitting central core model of ospf more flexible than ospf, but easier to make mistakes too.
Overview in lab 6 we discussed rip, which is the canonical example of a routing protocol built on the distancevector algorithm. Rip and ospf o exterior routing n routing between autonomous systems n only one exterior routing protocol is usually used for exterior routing n examples. Openshortestpathfirst ospf is the most widely used interior gateway protocol routing protocol on the world because it is a public nonproprietary routing protocol while its biggest rival, eigrp, is a cisco proprietary protocol so other vendors cant use it edit. Sep 19, 2018 open shortest path first ospf is a widely used and supported routing protocol. These lessons will teach you everything, we start with the basics and work our way through the. Ospf tutorial to get you on the right path udemy blog. Give c second priority bdr in election ip ospf priority 50 interface loopback0 ip address 10. It was published by the ietf to serve as an interior gateway protocol replacing rip. Incoming update filter list for all interfaces is not set. The chapter starts by covering the basic ospf concepts.
Routing protocol is ospf 1 outgoing update filter list for all interfaces is not set. Ospf is a linkstate routing protocol with a complex set of. Open shortest path first ospf routing protocol dummies. Rip adheres to the following distance vector characteristics. Nonbroadcast multiaccess nbma is a particular challenge in any network environment. Ospf open shortest path first ospf is a standardized linkstate routing protocol, designed to scale efficiently to support larger networks. Dec 03, 20 default routes in ospf, default route configuration with cost, ospf special area types duration. Rip was one of the first true distance vector routing protocols, and is supported on a wide variety of systems. Routers will exchange pieces of information called lsas link state advertisement in order to build a complete topology database which we call the lsdb link state database. Routing protocol how it works mechanism and types of routing. Learn ospf configuration commands, ospf show commands, ospf network configuration process id, network id, wild card mask and area number and ospf routing in detail.
You should know how to define a routing protocol and understand which protocol is best to use in your network. Ospf employs a hierarchical network design using areas. You can set different process id from 165535 for each router. Ospf tutorial december 3rd, 2010 go to comments for example, r1 wants to find out if it has any neighbor running ospf it sends a hello message to the multicast address 224. Ospf routing messages ospf exchanges messages using directly ip packets with a protocol number 89 in the corresponding eld of the ip header hello. In this article we will learn about the ospf routing protocol. This paper examines how ospf works and how it can be used to design and build large and. This tutorial introduces you to open shortest path first ospf, a linkstate routing protocol. Basic ospf configuration for internal router abr and asbrs 44. Optional md5 authentication configured ip ospf authentication messagedigest ip ospf messagedigestkey 1 md5 foobar. Route redistributionroutes learned via any ip routing protocol can be. It is used to allow routers to dynamically learn routes from other routers and to advertise routes to other routers. Open shortest path first ospf is an active routing protocol used in internet protocol.
When many ospf routers are part of the same network, information about all of the routes in a network are learned by all of the ospf routers within that networktechnically called an area. Eigrp has become a public routing protocol since 20. Ospf is a standardized linkstate routing protocol, designed to scale efficiently to support larger networks. When a link state router begins operating on a network link, information associated with that logical network is added to its local link state database lsdb. 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. Routing information protocol distance vector routing share the most you know about the entire autonomous system share with all your direct neighbors, and them only share periodically, e. Comparison of rip, ospf and eigrp routing protocols based on. Like ospf, isis runs the dijkstra shortestpath first spf algorithm to create a database of the networks topology and, from that database, to determine the best that is, shortest path to a destination. Routing protocol packets are sent with type of service tos of 0. Open shortest path first ospf is an open standard not proprietary and it.
Three typical types of routing protocol are chosen as the simulation samples. Important ospf interview questions and answers with pdf to. Routing protocol how it works mechanism and types of. Ospf open shortest path first link state or spf technology.
Ospf is developed by internet engineering task force ietf as one of the interior gateway protocol igp, i. Open shortest path first ospf inetdaemons it tutorials. Ospf open shortest path first is a popular linkstate routing protocol. How to configure ospf routing protocol using packet tracer. Apr 25, 2015 the router ospf command enables ospf routing on the router, and the 1 before osfp is the process id of the osfp protocol.
It then briefly explains why ospf is considered an improved routing protocol over routing information protocol rip by covering how ospf discovers, chooses, and maintains routing tables. Open shortest path first ospf is an open standard not proprietary and it will run on most routers independent of make. This article introduced the ospf protocol and examined how ospf works. Ospf is a routing protocol used to determine the best route for delivering the packets within an ip networks. Comparison of rip, ospf and eigrp routing protocols based. Open shortest path first open shortest path first ospf is an openstandard link state routing protocol. In this lab, you will set up a network that utilizes ospf as its routing protocol. Ospf was originally defined as the 2 nd version in rfc 2328. Ccna training comprehensive guide on ospf routing protocol. One of the most popular dynamic routing protocols available is the open shortest path first ospf. Bgp pdf created with fineprint pdffactory pro trial version.
In this lesson ill explain the basics of ospf to you and you will learn how and why it works. Home downloads download cisco ccnp routing pdf study guide. Open shortest path first ospf is a linkstate routing protocol that is used to find the best path between the source and the destination router using its own shortest path first. Open shortest path first ospf is a widely used and supported routing protocol. The open shortest path first ospf protocol is a link state protocol that handles routing for ip traffic. Particularly it is a link state routing protocol and includes into the group of interior gateway protocol. Simple ospf network need to create ospf routing process router configuration command router ospf specify the network running ospf should also specify the area 25. Open shortest path first a routing protocol based on the linkstate algorithm objective the objective of this lab is to configure and analyze the performance of the open shortest path first ospf routing protocol. Default routes in ospf, default route configuration with cost, ospf special area types duration. The ospf protocol is a linkstate routing protocol, which means that the routers exchange. Routing protocol is ospf 1 outgoing update filter list for all interfaces is not set incoming update filter list for all interfaces is not set router id 192. How to use and implement ospf as the protocol of choice.
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