Visitors to VTC.com will be able to view all introductory videos for each training course.
Free Trial Members will gain access to first three chapters for each training course.
Full Access Members have full access to VTC.com�s entire library of video tutorials.
Welcome into the first lab for OSPF. In this lab, we're going to take a basic routed network and we're going to set up OSPF on it. Now this OSPF network again is going to be pretty basic. We're going to set everything up in a single area. We're not going to get too fancy with the config in this very first lab, this is basically just to show you what's necessary to get the OSPF processes up and running on your router and how to verify that everything's running. So, here is our GNS3 lab and yeah, I know, you might be looking at this and saying, well that doesn't look a simple network, you've got five routers and switches and WAN links and everything. This is pretty simple for OSPF, at least in a single OSPF area. This allows us to demonstrate what happens on a Broadcast Network. We've got three routers down here so that one of them will be the Designated Router and one will be the BDR and you'll get to see how you can influence that decision based upon the priority and you also have the WAN links up here to show you how it works over a Point-to-Point WAN link. Now as with all the other labs, this lab is available in the Work Files for this course and I'm using the 3640 Router platform. So with all that said, let's jump right in. And we're on our corporate router and you'll see that the network is up and running. If we show the CDP neighbors we see the router's in Georgia in Tennessee as well as our sales and engineering sections here in our corporate office. So the first thing we do is we get the OSPF process up and running. For that, we go into Config Mode, like with everything else and we will enter Router OSPF, you see the OSPF subcommand there, OSPF and then it wants a Process ID. Now unlike EIGRP or BGP as you'll see elsewhere in the course, this Process ID for OSPF is only locally significant and you can give it a process ID of one to 65,535 and you could give a different Process ID on every router on the network and OSPF wouldn't care, because this Process ID is local. And just for the sake of documentation and the ease of troubleshooting, most network engineers give their OSPF Process IDs the same number across the entire network. In our case we'll just use process one, so Router OSPF one. We're now in Router OSPF Config Mode. So let's look at the commands that are available to us and you'll notice that one of the Commands that's obviously missing from OSPF is the AutoSummary. Normally that would be right up here under Auto Cost, or where Auto Cost is in this list. You'll recall OSPF does it's Summarization at the ABRs only. You cannot set up Summarization elsewhere. Therefore OSPF does not Auto Summarize. Again all the routers in a single area will know all the individual routes to all of the networks across every router. So if we look further down the list here, you'll see we have the Network Command and we'll use the Network Command to, to put in some of our loopback networks here in a second, but there's also another way that works in newer IOS versions and that's IOS version 12.3.11 I believe and above, where you can actually go into the interface and tell the individual interface I want to use this interface for OSPF. Honestly, I prefer it that way, just because I know what interfaces I'm going to be running the OSPF processes on or what networks I'm going to advertise under OSPF to be more accurate. But obviously we're going to show you both ways to do it because both ways are correct and honestly if you're working on a network with older IOS versions, you know, 12.2 is, is pretty common, pretty prevalent in use. Then you'll need to know how the Network Command works and how it's a little peculiar, especially on loopback interfaces. So the first thing we're going to do is add our WAN networks into the OSPF infrastructure. And you'll see our WAN networks are 192.168.1.0 192.168.1.4. There are two individual interfaces as you can see if I do Do Show IP Interface Brief. You can see we have serial 00 and serial 01. So obviously we could do these two networks individually but this is one of the peculiarities of the Network Command with OSPF. And I know normally when you say oh this command has a little peculiarity or it's a little different and some people go, oh great what's broken about this command? Actually I kind of like the way that the Network Command works in OSPF. With OSPF you can actually put in Network, in this case we'll do 192.168.1.0 with a subnet mask of 255.255.255.0. Now you may be thinking, well, you don't actually have a network interface that matches that, you're not routing that network. And you're absolutely correct, however with OSPF, what this command actually does is say, any interface that fits in this network and this subnet mask, enable the OSPF processing on that interface. So by typing this one command I am enabling OSPF on both of these serial interfaces in one fell swoop, I don't have to have two Network Commands in here. Now obviously I could put them in there, I could do 192.168.1.0 with a / 30 or .252 subnet mask and do the same thing with the .4 network but why go to all that trouble. So we've got the Network Command in here and since OSPF has the concept of distinct areas, we have to actually set the OSPF Area ID for these networks. So we'll do Area 0 and that's it. Once we do that, now we are routing these networks via OSPF. Obviously there's no other OSPF neighbors out there for it to talk to, so if we were to look at OSPF it would be in a Down State, because it's saying hey, I'm, I'm all alone in the world, there's no one else to talk to and I'm so lonely. We'll fix that here in just a little bit. We'll continue on with our Basic OSPF Configuration in the next video.
| Course: | Implementing Cisco IP Routing (642-902 ROUTE) |
| Author: | Greg Dickinson |
| SKU: | 34291 |
| ISBN: | 978-1-61866-028-2 |
| Release Date: | 2011-12-28 |
| Duration: | 10 hrs / 105 lessons |
| Work Files: |
Yes |
| Captions: | No |
| Compatibility: |
Vista/XP/2000, OS X, Linux QuickTime 7, Flash 8 |