Configuring ospf on cisco router pdf

Ospf configuration in packet tracer lab with pdf networking. Ospf open shortest path first is an open standard routing protocol, meaning any vendor like cisco, juniper, brocade can implement its features. Configuring ospf over different physical networks configuring ospf for pointtomultipoint broadcast networks summary steps 1. In the configuration mode, type router ospf to enter global ospf profile. Authentication to ospf packets both password and md5 authentication. How to configure ospf on cisco routers with example. 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. After ospf is enabled, tune the update timers and configure authentication. Configuring ospf for pointtomultipoint broadcast networks 14. You can set different process id from 165535 for each router.

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. Basic ospf configuration on cisco routers new youtube. Ospf is a standard internal gateway protocol igp that is used by many different types and sizes of companies. Jun 11, 2019 this ospf lab is created in packet tracer and you will learn the ospf single area configuration from this lab. Today we will discuss how to configure ospf in cisco routers. This tutorial explains how to configure ospf routing protocol step by step. This is done by using the router ospf processid global configuration command. Ospf configuration step by step guide computernetworkingnotes. Configuring the asa as a designated router or a designated backup router. Single area ospf configuration with example icnd1 100105. First, configure loopback interfaces to provide stable ospf router ids. Using show ip ospf interface we see md5 authentication is enabled and we are using key id 1.

All right folks, here is the moment, the majority of us have been waiting for, configuring a dynamic routing protocol, open shortest path first, or ospf. If your network consists of multiple areas, you must also configure a backbone area 0. First, we will configure r1 and r2 for the backbone area. The ospf mib defines an ip routing protocol that provides management information related to ospf and is supported by.

This article is the fourth in a series of articles covering the basics of cisco networking. Configuring ospf default information originate duration. 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. June 24, 2011 this module describes how to configure open shortest path first ospf. Configure the ospf router identifier by entering the router id configuration value. How to configure rip on a cisco router rip routing information protocol is one of the routing protocols you need to understand if you want to pass the cisco ccna exam. Basic ospf configuration for internal router abr and asbrs 40. Next, you need to define on which interfaces ospf will run and what networks will be advertised.

Below output shows the adjacency states and the elected drbdr for the above topology. In this lab we will learn to configure multi area ospf using cisco packet tracer. Now you have to configure ospf such that devices in area 0 can easily communicate with devices in area 1. Configure the ospf router identifier by entering the routerid configuration value. We want to enable eigrp only on the subnet connected to the interface fa00. In the following example, the output for the show ip ospf and show ip ospf database nssa commands shows an open shortest path first notsostubby area ospf nssa area where rfc 3101 is disabled, rfc 1587 is active, and an nssa area border router abr device is configured as a forced nssa lsa translator. Ospf supports md5 and clear text neighbor authentication. If ospf router id needs to be routable, configure a loopback interface with the same ip address and include it under the ospf process. Just like with other routing protocols covered so far rip, eigrp first you need to enable ospf on a router. Home downloads download cisco ccnp routing pdf study guide. Then configure the ospf process and enable ospf on the appropriate interfaces. The router ospf command enables ospf routing on the router, and the 1 before osfp is the process id of the osfp protocol. Configuring route summarization when redistributing routes into ospf 17. This is how the topology of our network looks like after adding new router r4.

In below network topology diagram you can see there are two area area 0 and area 1. The following new commands are added to the command line interface cli. Open shortest path first open shortest path first ospf is an openstandard link state routing protocol. Lets start with all network commands to get ospf up and running. Routers using ospf are constantly exchanging data about known routes and state of connections. The other two switches in the other building are running ospf, i am trying to connect to the other building and access a server which is on a switch running ospf. For protocolindependent features, see the chapter configuring ip routing protocolindependent. This type of stub area is an extension to ospf created by cisco. By default both routers interface priority would have been 1 so the drbdr election process tie breaker would have been the router id, and in this case r2 would have became the designated router as it has a higher router id number and r1 would have became the dbr. Ospf support for unlimited software vrfs per pe router cisco. Globally, configuring ospf includes enabling the process and adding networks to be advertised.

Configuring ospf for pointtomultipoint broadcast networks 17. If you have no idea how rip works i suggest to read this lesson first where i explain how rip works. This helps in route summarization, in case these router ids need to be routed. To configure basic ospf to form a neighbor adjacency on a cisco router perform the following. Example basic ospf configuration for internal router abr and asbrs 35. Configuring ospf route summarization free ccna workbook. The network command defines to which area each interface will belong. It is the first step in configuring ospf on a router as done here on r1. Ospf is an interior gateway protocol igp developed by the ospf working group of the internet engineering task force ietf. How to configure multi area ospf lab in cisco packet tracer. Thus, if a router with a higher priority is added to the network, it will not automatically supplant an existing dr. How to configure ospf routing protocol using cisco packet.

Tsas receive a single type 3 lsa containing a default route to the abr. Select the vedge router by clicking its system ip address. 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 cli configuration commands for cisco routers cisco ios routers are probably the most complete. A priority of 0 will prevent the router from being. This tutorial explains how to configure ospf routing protocol step by step with practical example in packet tracer. When configuring any ospf router, you must establish which area assignment to enable the interface for. The way discussed in this lab is the new way of configuring ospf to operate on interfaces. Below output shows the adjacency states and the elected drbdr for. Ip address configured with the ospf router id command. Or scroll through the list of devices in the device table. Basic ospf configuration for internal router abr and asbrs 52.

You can use real cisco devices or any other network simulator. In following figure there are the three routers with. Cisco ios router configuration commands cheat sheet pdf. Cisco routers derive the router id in one of three ways and with the following precedence. The next step in configuring ospf is to specify which router interfaces are included in ospf using the network command, also mentioning ospf area the interface belongs to. This ospf lab is created in packet tracer and you will learn the ospf single area configuration from this lab. Confirm your configuration by entering the show routing. An ospf area consists of routers configured with the same area id.

To include a router in a specific area, the common area id must be assigned and an interface identified. Ospf has some basic rules when it comes to area assignment. Configure ospf router ids the ospf router id is used to uniquely identify the router in the ospf routing domain. If you are done configuring the device, commit the configuration. Totally stubby area permits type 1 and 2 lsas while blocking types 3457 lsas. In a previous post, i have published a cisco switch commands cheat sheet tutorial. How to configure ospf routing protocol using cisco packet tracer. Identify the network interfaces that should run ospf.

Here is an example of a router configured with the ospf routing protocol. Link state routing protocols advertise the state of their links. Locate the vedge router using the sort options dropdown and the search box. Configuring ospf on a catalyst 3560g switch to connect to our building next door by way of fiber.

In ospf, you can only summarize routes at an abrasbr on the link facing the inbound towards the network. When direct channel between r1 and r3 fails, traffic flows over r2 router. When enabling ospf on r2, it would have got the rid of 10. A priority of 0 will prevent the router from being elected dr or bdr. This article takes a look at the configuration of open shortest path first ospf. Oct 17, 2012 the router ospf command entered in global configuration mode with autonomoussystemnumber argument creates an ospf routing instance. The ospf router id is used to uniquely identify the router in the ospf routing domain. Just like eigrp, ospf configuration is divided into two parts the global configuration and the interface level configuration. For configuring ospf and advertising networks use the same commands mentioned in exercise 1. Ospf support for unlimited software vrfs per pe router. Configuring ospf for pointtomultipoint broadcast networks 12. If your network consists of multiple areas, you must also configure a. Global configuration mode, we type in router, and we specify ospf, and now there is this number just sitting there, a 1 in this case. How to configure ospf on cisco routers with example commands.

Configuring ospf areas techlibrary juniper networks. Ospf was designed expressly for ip networks and it supports ip subnetting and tagging of externally. Ip address configured with the ospf routerid command. This is a basic labs regarding ospf single area configure related to ccna or icnd12 exam. To do so, first we need to enable ospf in our router. The router ospf command entered in global configuration mode with autonomoussystemnumber argument creates an ospf routing instance. Verify that the summary route is being propagated correctly by viewing the routing table on r1. Jul 26, 2017 to configure basic ospf to form a neighbor adjacency on a cisco router perform the following. Choose the router id ip address from the same ospf area address space the router belongs to.

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