Understanding basic open shortest path first ospf routing principles not only applies to the ccnp certification but to all cisco based certifications. Ospf can scale to the largest lans but can also start out small. Link state routing protocols advertise the state of their links. 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. If you remember the ospf configuration for ipv4, the networks are added to the ospf process with network statements under ospf router configuration mode. The idea is the same but some of the commands are different. Ospf employs a hierarchical network design using areas.
Download this cisco router configuration commands cheat sheet in pdf format at the end of this post herethe most important cli commands are included that will help you in the field. For protocolindependent features that include ospf, see the chapter configuring ip routing. To do so, first we need to enable ospf in our router. Ospf configuration in packet tracer lab with pdf networking. Audience the cisco ios documentation set is intended for users who configure and maintain cisco networking devices such as routers and switches but who may not be familiar with the configuration and.
In this lesson ill explain the basics of ospf to you and you will learn how and why it works. Configuring route summarization when redistributing routes into ospf 23. Cisco router configuration commands cli cheat sheet. This paper examines how ospf works and how it can be used to design and build large and complicated networks. Ospf open shortest path first is an open standard routing protocol, meaning any vendor like cisco, juniper, brocade can implement its features. Create an ospf feature template to configure ospf parameters, as described in this article. The cost was configured with the ip ospf cost interface configuration command. For protocolindependentfeaturesthat work with ospf, see the configuring ip routing protocolindependent. If im correct, this network type emulates a pointtopoint connection where no drbdr is required and no need to define manual neighbors in order to establish the adjacencies between ospf routers in nbma network like framerelay. Above we have r1 and r2 in area 0, the backbone area. Here in this lesson, we will learn basic ospfv3 configuration in a small network consisting of three cisco routers, three layer 2 switches and three computers. Ospf p art 1 protocol header type attributes algorithm metric linkstate dijkstra cost bandwidth ad.
Ospf will form neighbor relationships with adjacent routers in the same area. Open shortest path first ospf is a linkstate routing protocol, rather than a distance vector protocol. Ospf adheres to the following link state characteristics. Ospf uses the dijkstra shortest path first algorithm to determine the shortest path. Im a trainee in networks, and i had an exercice of routing protocols and a static route ospf, eigrp, rip, et static. How to configure ospf stub area previously i explained the different ospf special area types called stub areas. The retooled cisco certified network associate ccna exam has been updated to reflect the latest technologies and job roles. Scenario international travel agency ita maintains a complex ospf environment. Configure passive interface for the user vlans and stubnetworks.
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. Since these kinds of posts are useful as a reference for many people, i have decided to create also a cisco router commands cheat sheet with the most useful and the most frequently used command line interface. Hi everyone, im trying to understand ospf network types. Basic ospf configuration for internal router abr and asbrs 40. Second step is to configure the ospf router id of the other abr. This module describes how to configure open shortest path first ospf. Ospf open shortest path first protocol is a wellknow routing protocol that is widely used today.
I have this setup with a hybrid of equipments from cisco and ubiquiti edge routers and vyos. 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. This article is about the ospf configuration in packet tracer. A concrete understanding of how ospf routing works is fundamental for any small or large network. Ospf configuration step by step guide this tutorial explains how to configure ospf routing protocol step by step with practical example in packet tracer. Router ids must be unique to prevent unintended ospf database problems. The ospf routerid is used to identify a specific device within an ospf database. The figure below shows a network diagram in which ospf area 1 is defined as the stub area. Ospf is perhaps the most widely used interior gateway protocol igp in large enterprise networks. We configure the virtuallink between abrs and we use the area virtuallink command. Ospf commands use the commands in this chapter to configure and monitor the open shortest path first ospf routing protocol.
Create separate ospf templates for the two ospf routing types. The configuration of ospf routing protocol is easy as rip routing. 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 configuration task list ospf typically requires coordination among many internal routers. This type of stub area is an extension to ospf created by cisco. This keeps track of external routes injected by exterior protocols such as bgp. To create a scalable cisco ospf configuration, you need to follow the best practices. Open shortest path first ospf is a routing protocol developed by internet engineering task force ietf.
Although basic ospf configuration can be very simple, ospf provides many extra features that can get really complex. Ospf configuration guide americas headquarters cisco systems, inc. The revised exam tests networking professionals understanding of foundational and, at a basic level, emerging topics. Use the ip ospf authentication command to specify this password. Jul 26, 2017 how to configure basic ospf by brandon carroll in networking on july 26, 2017, 12. Ospf is link state routing protocol that works on the concept of areas. Now it is time to go deep and combine virtual link, lsa types and etc.
Here is the configuration to enable md5 authentication. Ospf open shortest path first is a popular linkstate routing protocol. In my introduction on ospf i explained why we sometimes use multiple areas for ospf and in our configuration example, i showed you how to configure ospf for a single area. The task is to optimize ospf routing, which creates the need to design and configure multiarea ospf. I tried to do the redistribution between the lans but it doesnt work for me, my ping command fails, i. How to configure ospfv3 ipv6 routing in cisco routers. The open shortest path first ospf is a routing protocol for wide area networks and enterprise network.
Ospf is a standard internal gateway protocol igp that is used by many different types and sizes of companies. How to configure basic ospf by brandon carroll in networking on july 26, 2017, 12. Optional md5 authentication configured ip ospf authentication messagedigest ip ospf messagedigestkey 1 md5 foobar. I will give you some basic overview about ospf and then will provide the details of these configuration by practically configuring a lab. Ospf configuration, the router sends a notification message to the console stating that a neighbor relationship with another ospf router has been established. You can see that r1 has learned about the network 192. Ospf interarea route summarization cisco community. In 2008 free ccna workbook originally started as a sharable pdf but quickly evolved into the largest ccna training lab website. In ospfv3, the configuration is entirely different. Ospf is commonly used in large service provider networks or large financial institutions. Ospf allows for the transfer and tagging of external routes injected into an autonomous system. For ospf configuration information and ex amples, refer to the con figuring ospf chapter of the network protocols configuration guide, part 1.
In a previous post, i have published a cisco switch commands cheat sheet tutorial. In reality, the bandwidth to each neighbor is different, so the cost should differ. Ospf is a classless routing protocol that supports vlsm and cidr, and uses the shortest path first spf algorithm to calculate the best path to a network. Authentication of peers is important as well, and you should use routemaps for. In the next series of lessons i will show you the configuration of each ospf stub type. Areas have to be connected to the backbone area but if they arent we can fix it with a virtual link. The router id can be used to break a tie in the election process. In our example, we will examine the figure below deeply.
Define area 9 as a totally stubby area area 9 stub nosummary. Basic ospf configuration for internal router abr and asbrs 41. Authenticate adjacencies with md5 ip ospf authentication messagedigest. Download cisco ccnp routing pdf study guide snabay. About ospf open shortest path first ospf is one of the dynamic routing protocols amongst others. While ospf can be complex to configure, its basic configuration isnt difficult. Ospf configuration step by step guide computernetworkingnotes. A number of different cisco ios ospf configuration commands are available, but at its most basic, ospf configuration uses three commands. Jun 11, 2019 this article is about the ospf configuration in packet tracer.
This article is the fourth in a series of articles covering the basics of cisco networking. Configuring multiarea ospf objective in this lab configure a multiarea ospf operation, interarea summarization, external route summarization, and default routing. The ospf network command uses a combination of networkaddress and wildcardmask. Ospf configuration guide cisco ios xe 3se catalyst 3850.
Configure ospf area parameters p1c112 network protocols configuration guide, part 1 on any pointtomultipoint interf ace broadcast or not, the cisco io. First you need to specify the area 1 where we need the virtuallink which is area 1 in my example. This article takes a look at the configuration of open shortest path first ospf. Basic ospf configuration for internal router abr and asbrs 52. In this document we discussed about route summarization between the areas.
How to configure ospf in cisco router letsconfig from basic. How to configure ospf routing protocol using cisco packet. Configure the interfaces on the r1, r2, and r3 routers with the ip addresses from the table under the topology diagram. Routing configuration guide, cisco ios xe release 17. Ospf network type nbma nonbroadcast multiple access uses only unicast communications, so it is the preferred way of ospf configuration in situations where multicast addressing is not possible or desirable for some reasons. One of the type im having confusion is pointtomultipoint. We start with the definition of router id, and then continue on network and passive interface definition. But just before we get to configure, lets have an overview of ospf. Cisco sdwan documentation is now accessible via the cisco product support portal. Jun 28, 2017 it is time to take a look to configuring ospf open shortest path first with an ospf configuration example. I dont know about you but i love my navigation system. This time, well take a look how you can configure multi area ospf. Open shortest path first ospf routing protocol dummies.
Open shortest path first open shortest path first ospf is an openstandard link state routing protocol. This lab will discuss and demonstrate the configuration and verification of the ospf routerid. Ospf configuration in packet tracer computer networking. Ospf is an interior gateway protocol igp developed by the ospf working group of the internet engineering task force ietf. In lab 91, the process of the routerid determination was discussed and through out section. Download cisco ccnp routing pdf study guide snabay networking. The router ospf processid command is the beginning of any cisco ios ospf configuration.
Ospf p art 2 configuration example interface serial00 description wan link. To configure a netowork for ospf properly there are some steps. For basic ospf configuration, the followin scenario will be a good example. How to configure ospf on cisco routers with example commands.
Cisco ospf configuration according to best practices. Once you are in the router ospf configuration submode, configure the lan network 172. With the basic overview of ospf configuration you can learn, how to configuration ospf on any cisco device this will provide you the basic. This chapter focuses on a number of objectives falling under the ccnp routing principles. The process id number is a locally significant process identification number and this does not need to match neighboring routers. In a previous lesson i demonstrated how to configure plain text authentication for ospf. Configuration dospfv2 et ospfv3 en cisco ios cisco. Cisco ios documentation describes the tasks and commands available to configure and maintain cisco networking devices. For ospf configuration information and examples, refer to the configuring ospf chapter.
On any pointtomultipoint interface broadcast or not, the cisco ios xe software assumed that the cost to each neighbor was equal. Cisco ios router configuration commands cheat sheet pdf. Configure passive interface default under ospf routing process. If you studied cisco s ccna you have learned that when you use ospf all the areas have to be directly connected to the backbone area. Ospf is a classless protocol, and thus supports vlsms. How to configure ospf routing protocol using cisco packet tracer.
Ospf was designed expressly for ip networks and it supports ip subnetting and tagging of externally derived routing information. Give c second priority bdr in election ip ospf priority 50 interface loopback0 ip address 10. This tutorial explains how to configure ospf routing protocol step by step with practical example in packet tracer. Jun 22, 2017 in this article we will make an example for advanced ospf configuration. 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. Ospf is standardsbased which means it is available on routers by cisco as well as other vendors, making it a vendorneutral routing protocol.
Cisco ospf configuration commands for checking adjacency, dr bdr election and stub area. Cisco any yes yes 1040 cisco full mesh no yes 1040 cisco pointtopoint area 0 a backbone area 9. This tutorial will give you an easy guide of configuring basic ospf on a cisco router. Just two routers in the same area, nothing special. In this article we will see how to configure ospf step by step. 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. My cisco nexus configured with hsrp with all the svis on 192. Configuring route summarization when redistributing routes into ospf 19. We talked about ospf basics and made an ospf configuration for beginners on our course.
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. View a summary of the ospf linkstate database entries. Basic ospf configuration for internal router abr and asbrs 44. And, enable specific interfaces using no passive interface. Ospf uses a routing metric of cost that in ciscos implementation is based mainly on the bandwidth of a link. Feature information for configuring ospf ttl security check and ospf graceful. For protocolindependent features, see the chapter configuring ip routing protocolindependent. Today we will discuss how to configure ospf in cisco routers. Home downloads download cisco ccnp routing pdf study guide. By collecting connectivity information from all of the devices on the network, ospf. This of course leads to more complexity in the configuration and troubleshooting of ospf networks. Keep this in mindyou need to configure the ospf router id and not the ip address of the abr.
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