Just like with other routing protocols covered so far rip, eigrp first you need to enable ospf on a router. Router ids must be unique to prevent unintended ospf database problems. For configuring ospf and advertising networks use the same commands mentioned in exercise 1. Once you are in the router ospf configuration submode, configure the lan network 172. The intelligent use of vlsm is very useful in ip address allocation. Ospf basic configuration ospf basic configuration pearson. By default, the cost is calculated by using the formula cost 10 8 bandwidth. Enter the configure terminal command to enter global configuration mode. I need to use the router ospf command to get into the ospf configuration.
Ospf is an open standard protocol, you learn more why we use ospf and ospf quiz from here. According to network diagram, routers r3 is in the area 0. To do so, first we need to enable ospf in our router. Ospf configuration guide cisco ios xe 3se catalyst 3850. Ip address configured with the ospf router id command. How to configure ospf on cisco routers with example. If you want to configure either a router or switch to retrieve its ip configuration information from a network dynamic host configuration protocol dhcp server, then you can commands like the following example. 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.
The ospf mib defines an ip routing protocol that provides management information related to ospf and is supported by. The configuration of ospf in a large scale implementation can be a bit hard to follow when quickly looking over a configuration, but if the network engineer knows the base ospf concepts and sits down with the configuration then they should be able to figure out the intention of the ospf design. Ospf configuration in packet tracer lab with pdf networking. The network command defines to which area each interface will belong. Basic router configuration arvutiteaduse instituut. 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. So, configure a router id that you can actually associate with the router. Router4 connects to both areas that is area 0 and area 2, which makes him an area border router, while router5 is in area 2 router r3 and r5 configuration are same as we learn in above single area configuration lab but configurations of router r4 is as followi. Router b and router a are supposed to be configured with ospf. This ensures less processing on routers that are not listening to ospf packets. Configure ospf router ids the ospf router id is used to uniquely identify the router in the ospf routing domain. Ospf has some basic rules when it comes to area assignment. Today we will discuss how to configure ospf in cisco routers.
Ospf configuration guide cisco ios xe 3se catalyst 3850 switches iii. Enter the router ospf command and follow by the processid. Backbone area is created during routeros installation and additional configuration is not required. After that we will configure ospf as our routing protocol. First, we will configure r1 and r2 for the backbone area. Use in router configuration mode ospf router id ipaddress command to set the ospf router id for the system. In a previous lesson i demonstrated how to configure plain text authentication for ospf. For ospf configuration information and ex amples, refer to the con figuring ospf chapter of the network protocols configuration guide, part 1.
Jan 15, 2020 how to configure ospf routing on cisco router with packet tracer. Thus, if a router with a higher priority is added to the network, it will not automatically supplant an existing dr. This is a basic ospf configuration lab using two routers. This routing protocol maps the entire network using the spf algorithm and provides a fast convergence as a result of a failure on a router on the network. The reliable way to change the router id is either to reboot the router or to remove the ospf configuration and then re configure ospf.
With ospf, there is no limitation on the hop count. In ospf, routing information is exchanged between autonomous systems, which are groups of networks that share routing information. We will start by configuring ospf on routers r2 and r3. Configuring the rid is as simple as using the router id command. How to configure ospf in cisco router letsconfig from basic. Using two routers ospf configuration have been done in this lab. Create one loopback interface in both routers and configure ip address. Configure routers to log messages to the syslog server. A priority of 0 will prevent the router from being elected dr or bdr. The following illustrates the output of the show ip ospf interface command on a frame relay serial interface. Configuring route summarization when redistributing routes into ospf 23. A number of different cisco ios ospf configuration commands are available, but at its most basic, ospf configuration uses three commands.
Ospf is a routing protocol used in wan or business networks. Each ospf router requires a unique router id, which is the highest ip address configured on a cisco router or the highest numbered loopback address. Cisco ospf configuration according to best practices. In following figure there are the three routers with.
In this example we have two ospf areas that is area 0 and area 2. Which we can to prove this is going over the mpls and be label switched and not routed, lets do a trace. 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. I have used cisco packet tracer software to demonstrate the ospf configuration. Device 3 is configured as the nssa autonomous system border router asbr. It is defined as ospf version 2 in rfc 2328 1998 for ipv4. The ospf router id is used to uniquely identify the router in the ospf routing domain. Ospf adjacency process goes through the seven states. Configure ospf in two routers and check adjacency state, routing table and lsdb. The router ospf processid command is the beginning of any cisco ios ospf configuration.
The updates for ipv6 are specified as ospf version 3 in rfc 5340 2008. Use the highest active interface ip address that is configured on the router. In lab 91, the process of the router id determination was discussed and through out section. Ospf commands area nssa p1r232 network protocols command reference, part 1 area nssa to configure an area as a not so stubby area nssa, use the area nssa command in router configuration mode. Cisco routers derive the router id in one of three ways and with the following precedence. You can manually configure the cost with the ip ospf cost command. This is a basic labs regarding ospf single area configure related to ccna or icnd12 exam. Here we assume that all the interfaces including loopback interfaces, their speed, duplex and descriptions have been configured. Ospf, on the other hand, addresses most of the issues previously presented. Identify the network interfaces that should run ospf. 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. Configuration examples for ospf nonstop routing 94. Add an accesslist on the serial interfaces of both routers a and c.
This if you are learning or preparing for ccna certification or ccna training then this lab is for you. Ospf is standardsbased which means it is available on routers by cisco as well as other vendors, making it a vendorneutral routing protocol this is in contrast to enhanced interior gateway protocol eigrp that is cisco proprietary, and hence available only on cisco routers. Ospf commands use the commands in this chapter to configure and monitor the open shortest path first ospf routing protocol. This part explains these states with dr bdr selection process in detail with examples.
If a hello packet is not received in four times the hello interval, or 120 seconds, the neighbor router is considered dead. You can set different process id from 165535 for each router. To remove the nssa distinction from the area, use the no form of this command. Jul 26, 2017 to configure basic ospf to form a neighbor adjacency on a cisco router perform the following. The router id can be set to be the same as the system interface address loopback address. It is using a default route to get outside of its network, to the next hop on router b. Next, you need to define on which interfaces ospf will run and what networks will be advertised. How to configure cisco 2600 routers router computing. In the following example, an open shortest path first ospf stub network is configured to include ospf area 0 and ospf area 1, using five devices. Open shortest path first ospf is a routing protocol developed by internet engineering task force ietf.
Cisco ios router configuration commands cheat sheet pdf. How to configure ospf routing protocol using cisco. Create an ospf feature template to configure ospf parameters, as described in this article. First of all, we will configure the routers interfaces. Basic cisco commands by marcus nielson 2014 configuring basic switch settings switch examples.
Open shortest path first ospf is a routing protocol for internet protocol ip networks. The router ospf command enables ospf routing on the router, and the 1 before osfp is the process id of the osfp protocol. Router b is just a central router, connecting router a to router c. It is the first step in configuring ospf on a router as done here on r1. Jun 11, 2019 this ospf lab is created in packet tracer and you will learn the ospf single area configuration from this lab. So, this is what you need to do on r1 router ospf 1 router. We would also configure md5 authentication for ospf on fa00 of r2 and r3, using cisco as the authentication key. Ospf p art 2 configuration example interface serial00 description wan link ip address 172.
What is the recommended cisco best practice for configuring an ospf enabled router so that each router can be easily identified when troubleshooting routing issues. This is done by using the router ospf processid global configuration command. Router a is to block all ping traffic from network 192. In a previous post, i have published a cisco switch commands cheat sheet tutorial. The ospf network command uses a combination of networkaddress and wildcardmask. Device 2 configured to be the nssa area border router abr. Ospf open shortest path first is an open standard routing protocol, meaning any vendor like cisco, juniper, brocade can implement its features. The configuration is pretty simple and requires only two major steps. Below output shows the adjacency states and the elected drbdr for the above topology. Lets start with all network commands to get ospf up and running. I want the border routers to be bdrs for area 0 but they should be dr for area 1 and 2 respectively. Use ospf process number 1 and ensure all networks are in area 0. Here is the configuration to enable md5 authentication. In cisco ios software, ospf enabled routers send hello packets every 30 seconds on nonbroadcast network types.
Use the no ospf router id to configure the ospf router id as the default value address of the loopback 0 interface. How to configure ospf routing protocol using cisco packet. The ospf router id is used to identify a specific device within an ospf database. This lab will discuss and demonstrate the configuration and verification of the ospf router id. So, this is what you need to do on r1 router ospf 1 router id 1. The idea is the same but some of the commands are different. Oct 17, 2012 it is the first step in configuring ospf on a router as done here on r1. Ospf configuration in packet tracer computer networking. Home downloads download cisco ccnp routing pdf study guide.
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. May 19, 2020 configuring the ospf router id free ccna workbook we are going to address the routers and configure ospf to ensure loopback to loopback connectivity between r1 and r3. 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. When configuring any ospf router, you must establish which area assignment to enable the interface for. This tutorial explains how to configure ospf routing protocol step by step with practical example in packet tracer.
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