Certification-Tests

Cisco Certification: Building Your Home Lab, Part II By Chris Bryant

In the first part of this home lab tutorial, CCNA and CCNP candidates can see that there are a LOT of choices when it comes to what to buy to build your own Cisco practice lab.

Having been there myself, I know it's confusing to decide how many routers or switches to buy, and what I need at the minimum to run labs and get some great hands-on practice. Let's take a look at some lab configurations and some other lab equipment you may need.

A starter practice lab will consist of two Cisco routers and one switch, hopefully a 2950. This is a good way to get started. You will need to make sure that the routers you purchase have Ethernet ports, and at least one serial port. If possible, get routers with BRI ports, so even if you're not configuring ISDN now, you'll be able to in the future. (You will need one additional device to make ISDN work in your lab, and we'll talk about that later in this article.)

You can practice setting IP addresses and testing IP connectivity over the Ethernet interfaces, and you can configure a point-to-point connection between the two serial interfaces. (You must know how to do that before you think of taking the CCNA exams!) Depending on the switch, you can also get some practice putting the Ethernet ports in different VLANs and working with the switch IOS.

This setup does have some limitations. You can't practice trunking or Etherchannels with one switch, and you can't set up a Frame Relay cloud with this configuration. It's a good start, but you should consider getting a few more routers, including one to serve as your Frame Relay switch.

What's a Frame Relay switch? Good question.

The Frame Relay Switch

As you know from your studies, Cisco routers are DTEs by default. The Frame Relay cloud is made up of DCEs.

In a lab environment, you need a device to serve as the Frame Relay cloud. This device will have DCE interfaces, and will actually be performing frame relay switching. But this isn't a switch in our lab - it's a Cisco router.

There are plenty of Cisco routers that make great frame relay switches. Get one of those and a couple of DCE/DTE cables, and you can configure the router as a frame relay switch and have your own working frame relay cloud in your lab!

The Cisco router you choose as your frame relay switch should have at least four serial ports, and if you can get more, great. It's always good to have spare ports.

If you get four Cisco routers, with one as your frame relay switch, you can set up a frame relay cloud and practice your hub-and-spoke frame configurations. Even better, as my labs do in my CCNA Study Guide, you can set up a frame relay cloud and a point-to-point Serial connection. This will help you get real hands-on practice with such features as EIGRP variance.

With that four-router configuration and one switch, you can get some great hands-on experience with many CCNA features that many candidates just read about. If you can add a second 2950 switch, you can practice different spanning-tree configurations, such as changing the root bridge of a given VLAN, working with VLAN Trunking Protocol (VTP), and configuring your own Etherchannel! (You will need some crossover cables to connect your two switches.)

Let's take a look at one more important piece of lab equipment: the ISDN simulator. You can't just take a straight-through cable and connect your BRI interfaces directly. You need a device called an ISDN simulator to act as the phone company in your home network. The newer simulators let you set your own phone numbers and SPIDs; most older ones have a preset phone number and SPID that you must use. Either way, you get truly valuable experience getting hands-on work with ISDN, especially watching PAP and CHAP debugs and understanding the authentication process.

ISDN simulators can set you back a few bucks. I recommend you visit www.ebay.com and search for ISDN simulator�. There are generally 20 - 30 used ones on there at any given time. Be careful to purchase one with at least a 30-day guarantee. They are robust devices for the most part, as there is one in my home lab that I've had for three years (when they were really expensive!), and it's never given me a bit of trouble.

There are many online vendors that will sell you a new one, but obviously the price is going to be higher. One company I've had good experiences with is www.vconsole.com. Make sure to shop around, as there are plenty of ISDN simulator manufacturers out there on the web. Vconsole is the only one I've purchased a new unit from, and the 10-port simulator I use in my classes has worked beautifully.

There is another piece of lab equipment that isn't necessary for your lab, but you'll find life is a lot easier with it. And just as the frame relay switch is really a router, so is this device: the access server.

Access servers are devices with an asynchronous port that an octal cable can connect to. What you do is connect your blue console cable (officially referred to as a -rollover cable-�) to the console port of your access server. You then take an octal cable, and connect one end of the cable to your Async port. The other end of the cable, as you'd expect from the name, consists of eight smaller RJ-45 connectors. Each one of those goes into the console port of one of your other lab devices, and you configure the access server to allow one-key access to each of the other devices in your practice lab.

The configuration of the access server is a simple one, and I'll have an example of configuring your access server and frame relay switch up later today.

Not everyone can start with a lab this size, so be careful when you buy your first routers. Make sure that they're not just giving you good practice now, but that they allow for future growth of your lab. As you add a frame relay switch, an ISDN simulator, and an access server, you'll get the hands-on experience you need to be successful on the job, acquire the self-confidence and troubleshooting skills needed in the testing room and on the job, and to solve any simulator question on your CCNA and CCNP exams with ease.

Have fun!

For a copy of his FREE "How To Pass The CCNA" or "How To Pass The CCNP" ebook, write to chris@thebr