Its newest implementation, version 2, which is explained in rfc 2328, is an open standard. The adv router id heading shows the router id of the advertising router, that is the router from which this lsa was received now the link state id heading is a little more tricky. Ospf is a standardized linkstate routing protocol, designed to scale efficiently to support larger. Ospf is commonly used in large service provider networks or large financial institutions. Ospf version 2 is documented in rfc 1583 a lengthy document that i find very difficult to read.
Network routing protocols igrp, eigrp, ospf, isis, bgp. Articulate the leader in rapid elearning and communications. Ospf employs a hierarchical network design using areas. These options are listed in the following output, followed by a discussion of a few of the key ones. Ospf is considered to be a linkstate protocol, unlike rip, ripv2 and igrp, this protocol is what ospf shines on. Ip address configured with the ospf routerid command. Open shortest path first ospf is an interior gateway protocol igp. For years cisco, juniper, and other major networking vendors. Troubleshooting of open shortest path first ospf routing protocol can be eased by using the most relevant options with the show command. To configure a netowork for ospf properly there are some steps. Ospf is considered a difficult protocol to configure and requires a thorough understanding of terms that are commonly used. Cisco is an active member of the ospf working group at the ietf, and is responsible for many of the ongoing enhancements to the protocol. Requirements there are no specific requirements for this document. Open shortest path first ospf is a linkstate routing protocol, rather than a distance vector protocol.
Mar 26, 2017 open shortest path first ospf is a routing protocol for internet protocol ip networks. Ospf can be used for serviceside routing, to provide reachability to networks at the local site, and it can be used for transportside routing, to enable communication between the vedge router and other viptela devices when the router is not directly connected to the wan cloud. 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. Gateway routing protocol eigrp is an example of a balanced hybrid routing protocol. View a summary of the ospf linkstate database entries from the command dropdown located in the right pane, select ospf database summary. Eigrp has become a public routing protocol since 20. The working group was formed in 1988 to design an igp based on the shortest path first spf algorithm for use in the internet. Route redistributionroutes learned via any ip routing protocol can be redistributed into any other ip routing protocol. Home downloads download cisco ccnp routing pdf study guide. 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. Instead of looking at hopcount like rip, ospf looks at.
Ospf open shortest path first protocol is a wellknow routing protocol that is widely used today. Optional md5 authentication configured ip ospf authentication messagedigest ip ospf messagedigestkey 1 md5 foobar. Jul 26, 2017 open shortest path first, or ospf, is a routing protocol thats based on open standards, meaning any vendor can implement its features. Eigrp has several advantages over routing information protocol rip and interior gateway routing protocol igrp, and even some advantages over open shortest path first ospf and. 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. To complete this chapter, this final major section examines one more routing protocol. Give c second priority bdr in election ip ospf priority 50 interface loopback0 ip address 10. Open shortest path first ospf protocol explained auvik. Rfc 1584 provides extensions to ospf for the support of ip multicast traffic. Eigrp adheres to the following hybrid characteristics. The most popular routing protocols used on internet protocol ip networks and internetworks, including routing information protocol rip, open shortest path first ospf, border gateway protocol bgp, and private networknetwork interface pnni. Comparison of rip, ospf and eigrp routing protocols based.
By using these information sources you can gather the essential information to resolving your network problems. Connect to router01 console and use the following ios commands to configure open shortest path first ospf protocol in router01. Open shortest path first ospf protocol configuration in router01. Troubleshooting your open shortest path first ospf routing protocol is eased by the show ip ospf command which provides information specifically addressed to this protocol. If an area has multiple abrs, then the summarization. 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. Open shortest path first ospf is an open standard not proprietary and it. Open shortest path first ospf is a routing protocol developed for internet protocol ip networks by the interior gateway protocol igp working group of the internet engineering task force ietf. A concrete understanding of how ospf routing works is fundamental for any small or large network. Nov 02, 2011 ospf is considered to be an interior gateway protocol which is like isis but unlike ospf isis runs on the datalink layer while ospf runs at layer three the network layer. In this lesson ill explain the basics of ospf to you and you will learn how and why it works. This paper examines how ospf works and how it can be used to design and build large and. For protocolindependent features that include ospf, see the chapter configuring ip routing. The book also briefly discusses two proprietary cisco protocols, intergateway.
Comparison of rip, ospf and eigrp routing protocols based on. The show ip protocols command, will show you the ospf process number and basic information about the. This module describes how to configure open shortest path first ospf. Ospf is an interior gateway protocol igp developed by the ospf working group of the internet engineering task force ietf. How to configure ospf routing protocol using cisco packet. Please refer the beginning of this lesson to view the open shortest path first ospf protocol configuration ios commands. This document is a specification of the open shortest path first ospf tcpip internet routing protocol.
Ospf is classified as an interior gateway protocol igp. This tutorial explains how to configure ospf routing protocol step by step with practical example in packet tracer. Ospf is widely used as an interior gateway protocol. Introduction open shortest first path protocol preferred igp the myth. Linkstate protocols use the shortest path first spf algorithm to populate the routing table. Sanctioned by the ietf, it is intended to become internets preferred interior routing protocol. Introduction to open shortest path first ospf protocol. Ospfprovideredgetocustomeredgepece protocol multipleospfinstancesospfprocessandavrf rplbasedtype3filtering lsapacing release3. Thats my introduction in to ospf and it is a somewhat complex protocol that needs a complete. Understanding the ospf linkstate routing protocol cisco press. Ability to run multiple routing protocols in the same router same prefix could be learnt via more than one routing protocol adminstrative distance is used to discriminate between multiple source connected, static and other dynamic protocols 20. Troubleshooting open shortest path first ospf routing ip. This is commonly referred to as multicast ospf mospf. In this article we will learn about the ospf routing protocol.
Define area 9 as a totally stubby area area 9 stub nosummary. Ospf will form neighbor relationships with adjacent routers in the same area. Ospf was designed expressly for ip networks and it supports ip subnetting and tagging of externally derived routing information. The ospf protocol is a linkstate routing protocol, which means that the routers exchange.
Open shortest path first ospf is a routing protocol for internet protocol ip networks. Th synchronization starts as soon as the adjacency is formed between neighbors. Introduction this document is a specification of the open shortest path first ospf tcpip internet routing protocol. All of this information is stored in the link state database lsdb. From this picture each router independently runs the shortest path first spf algorithm to determine the best path through the network. After gathering information from available routers it constructs a topology map of a network. Understanding basic open shortest path first ospf routing principles not only applies to. By collecting connectivity information from all of the devices on the network, ospf. Redistribution ospf, rip, eigrp, static cisco community. 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. Understanding the ospf linkstate routing protocol ipv4.
Ability to run multiple routing protocols in the same router same prefix could be learnt via more than one routing protocol adminstrative distance is used to discriminate between multiple source. Ospf adheres to the following link state characteristics. Ospf uses database descriptor dbd packets for this purpose. The open shortest path first ospf protocol, defined in rfc 2328, is an interior gateway protocol used to distribute routing information within. You can set different process id from 165535 for each router.
I then established an ospf session on both end of the link with the. Cisco any yes yes 1040 cisco full mesh no yes 1040 cisco pointtopoint area 0 a backbone area 9. Bgp version 4 bgpv4 is the current standard deployment. Some of the most common routing protocols include rip, igrp, eigrp, ospf, isis and bgp. It implements dijkstras algorithm, also known as the shortest path first spf algorithm. Additionalreferencesforospfnotsostubbyareasnssa54 featureinformationforconfiguringospf55 chapter 3 ipv6routing. Configuration ospf routeur cisco pdf this of course leads to more complexity in the configuration and troubleshooting of ospf networks. It uses a link state routing lsr algorithm and falls into the group of interior gateway protocols igps, operating within a single autonomous system as. 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. The open shortest path first ospf protocol is a link state protocol that handles routing for ip traffic. Ospf is a linkstate routing protocol with a complex set of options and features. This means that it distributes routing information between routers belonging to a single autonomous system. Create separate ospf templates for the two ospf routing types.
It uses a link state routing lsr algorithm and falls into the group of interior gateway protocols igps. Border gateway protocol border gateway protocol bgp bgp is a standardized exterior gateway protocol egp, as opposed to rip, ospf, and eigrp which are interior gateway protocols igps. Understanding basic open shortest path first ospf routing principles not only applies to the ccnp certification but to all ciscobased certifications. Ospf open shortest path first ospf is a standardized linkstate routing protocol, designed to scale efficiently to support larger networks. Eigrp enhanced interior gateway routing protocol is ciscos proprietary routing protocol based on. Introduction this documents lists best practices used in ospf design. Ospf is based on the shortest path first spf algorithm which is used to calculate the shortest path to each node. Ospf p art 1 protocol header type attributes algorithm metric linkstate dijkstra cost bandwidth ad standard protocols.
Like eigrp, ospf bases its metric by default on link bandwidth, so that ospf makes a better choice than simply relying on the router hopcount metric used by rip. Rfc 11 describes the first iteration of ospf and it was used in initial tests to determine whether the protocol worked. According to the ospf rfc, when a router is packaging all of its local, type1 router lsas into a single ospf packet, and adds an lsa header to the front of those lsas, the link state id field. Oct 22, 2014 its normal because the ospf protocol will share all the connected networks to that router. The router ospf command enables ospf routing on the router, and the 1 before osfp is the process id of the osfp protocol. Ospf, being a linkstate protocol, allows for every router in the network to know of every link and ospf speaker in the entire network.
However, this standard is seldom used and, most importantly, it is not supported by cisco. I have two locations that was recently activated for a client using mpls l3 vpns, the end to end circuit is working fine showing the remote network via bgp and is reachable via ping. Introduction to open shortest path first ospf protocol the open shortest path first ospf protocol is a link state protocol that handles routing for ip traffic. This paper examines how ospf works and how it can be used to design and build large and complicated networks. Virtual routing and forwarding vrf is a technology included in ip internet protocol that allows multiple instances of a routing table to coexist in a router and work. Open shortest path first ospf was designed as an interior gateway protocol igp, for use in an autonomous system such as a local area network lan.
Many options are available for the show ip ospf command. Ospf does elect a dr designated router and a bdr backup designated router the drs job is to update all other ospf routers which a called drothers. For linkstate routing protocol, it is required that the linkstate databases for all routers remain synchronized. Ospf shares information with every router in the network. Enhanced interior gateway routing protocol eigrp enhanced interior gateway routing protocol eigrp is a ciscoproprietary hybrid routing protocol, incorporating features of both distancevector and linkstate routing protocols. Cisco routers derive the router id in one of three ways and with the following precedence. Enhanced interior gateway routing protocol eigrp enhanced interior gateway routing protocol eigrp is a cisco proprietary hybrid routing protocol, incorporating features of both distancevector and linkstate routing protocols. Ospf best practise summarization techniques summarizing intraarea routes is recommended in most cases. Ospf open shortest path first is the most widely used igp interior gateway protocol large enterprise networks.
Routing protocol is ospf 1 outgoing update filter list for all interfaces is not set. In this post, ill discuss some of ospfs major principles, and then follow up with a simple configuration that brings up ospf between two cisco. As a linkstate routing protocol it was based on the linkstate algorithm developed for the arpanet in 1980 and the isis routing protocol. Review additional information about open shortest path first ospf in the technical support site area. For basic ospf configuration, the followin scenario will be a good example. Protocol igp developed by the ospf working group of the internet engineering task. Open shortest path first, or ospf, is a routing protocol thats based on open standards, meaning any vendor can implement its features. Difference between rip and ospf compare the difference. Open shortest path first ospf routing protocol dummies. The purpose of routing protocols is to learn of available routes that exist on the enterprise network, build routing tables and make routing decisions. I dont know about you but i love my navigation system. How to configure ospf routing protocol using cisco packet tracer.
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