Scad Programme

Archive for December, 2009

A CCNA or CCNP candidate who wants to be totally prepared for their exams is going to put together a home lab to practice on. With used Cisco routers and switches more affordable and plentiful then ever before, there’s really no excuse to not have one!

With the many different models available, there is some understandable confusion among future CCNAs and CCNPs about which routers to buy and which ones to avoid. You can take almost any set of Cisco routers and put together a home lab; part of the learning process is taking what equipment you have available and putting together your own lab! For those of you preparing to start your home lab or add to your existing one, this article will list the routers I use in my Cisco pods. You certainly don’t have to have all this equipment, but this will give you some good ideas on how to get started.

The most versatile router you can get for your CCNA / CCNP home lab is a 2520. These routers come with four serial ports, one ethernet port, and one BRI interface for ISDN practice. This mix of interfaces means you can actually use it as a frame relay switch while using the ethernet and BRI ports for routing. (There is no problem with using a lab router as both your frame relay switch and a practice router; for a frame relay switch sample configuration, visit my website!)

My pods consist of five routers and two switches, and three of the five routers are 2520s, due to their versatility. A recent ebay search showed these routers selling for $99 – $125, an outstanding value for the practice you’re going to get.

I also use 2501s in my home labs. These have fewer interfaces, but the combination of two serial interfaces and one ethernet interface allows you to get plenty of practice.

A combination that works very well is using three 2520s; one as my dedicated frame relay switch, one as R1, and another as R2. Add a 2501 as R3, and you can have a frame cloud connecting R1, R2, and R3, a direct serial connection between R1 and R3, an Ethernet segment that includes all three routers, and an ISDN connection between R1 and R2 if you have an ISDN simulator. That combination will allow you to get a tremendous amount of practice for the exams, and you can always sell it when you’re done!

2501s are very affordable, with many in the $50 range on ebay. It’s quite possible to get three 2520s and one 2501 for less than $500 total, and you can get most of that money back if you choose to sell it when you’re done.

With four routers to work with, you’re probably going to get tired of moving that console cable around. An access server (actually a Cisco router, not the white boxes we tend to think of when we hear “server”) will help you out with that. An access server allows you to set up a connection with each of your other routers via an octal cable, which prevents you from moving that console cable around continually. For an example of an access server configuration, just visit my website and look in the “Free Training” section.

Access server prices vary quite a bit; don’t panic if you do an ebay search and see them costing thousands of dollars. You do NOT need an expensive access server for your CCNA / CCNP home lab. 2511s are great routers to get for your access server.

One question I get often from CCNA / CCNP candidates is “What routers should I buy that I can still use when I’m ready to study for the CCNP?” The CCIE lab changes regularly and sometimes drastically when it comes to the equipment you’ll need. During my CCIE lab studies, I found that renting time from online rack rental providers was actually the best way to go. Don’t hesitate when putting your CCNA / CCNP home lab together, wondering what will be acceptable for the CCIE lab a year or so from now. None of us know what’s going to be on that equipment list, so get the CCNA and CCNP first – by building your own Cisco home lab!

1. Really provides better cooling for your computer hardware

We all know that heat can really kill the motherboard, processor and other chips that are found in a computer case. If the temperature is too much it can fry the chips and leave your computer worthless. The more work you do, the longer you do it, the higher the workload on the pc. This causes heat to build up inside your computer. The traditional cooling fan that you can find on the back of the power supply of your computer is normally not enough to get it all the cooling it needs. Even with the other fan attached to the processor chip, your computer will most of the time not get all the cooling it needs.

If you were to use a rack, this would help to give your computer the cooling it needs, since it gives you a lot more space, unlike computers that don’t have racks.

2. You’ll have better air circulation

Without adequate space for your computer, there won’t be good air circulation and this can damage many things in your computer. A rack mount computer therefore gets better air circulation than one without it. And this goes a long way in protecting your computer.

3. Prevents vibration when playing load music

Good computer racks out there have vibration-dampening tendencies to prevent the vibration of your computer- especially when listening to load music from your speakers. Without these vibration-dampening tendencies, your speakers and even compute can slowly slip off your desktop, thereby causing damage.

4. Give more space for your computer

Your rack mount computer has more space than others without one. You are able to do more work than if you didn’t have a rack for your computer.

If you take all the above advantages into consideration you will come to find that using a rack mount computer instead of one without a rack is the way to go.

When it works well, e-mail can be great. It’s hard to beat e-mail for everything from staying in touch with family to requesting information from businesses or other organizations. Want to send the same message to several people? Communicate with someone across the continent? Transmit photos, manuscripts or other information? For speed and efficiency, this virtually instantaneous medium is one of the most convenient features of modern life.

But e-mail is not without problems. If you key in the name of an intended recipient but your message keeps bouncing back, you might not be singing e-mail’s praises. Ditto for attachments that won’t open or other such nuisances. With just a little patience, though, you can readily overcome most e-mail problems. What follows are 4 common e-mail problems along with solutions for overcoming them.

Problem – Returned Messages

This may be the most frustrating of all e-mail problems. After taking the time to create a message, you click on the “send” button and consider your task accomplished. But the next thing you know, the message pops up in your in-box with a heading that it did not reach its intended recipient.

Solutions

First, take the simple step of checking to see that the address of your recipient has been entered correctly. This may seem obvious, but sometimes the only thing wrong is a misplaced letter, the use of “com” instead of “net”, or some similar error. If you know the correct address, this is a straightforward matter of double checking each character. If not, you might need to experiment by sending multiple messages, or by entering alternative addresses with slight variations. Under this approach, you simply keep track of which messages are bounced back and compare them with the overall list of addresses you used. If you sent four variations but only three were returned, you have solved the problem by the process of elimination.

Sometimes the source of your problem lies with the recipient. If messages to other addresses go through but fail here, try to contact the intended recipient by other means and report the situation. The cause may range from a temporary problem with the recipient’s server to a switch to another e-mail provider, to a full in box. In this case, simply waiting may be the best recourse. Or a phone call or other communication may be required on your part to obtain the correct e-mail address. If all your messages are being returned, you may have a connection problem. See below for more details.

Problem 2 – You Have Lost Your Connection

Sometimes a failure to send or receive e-mail can be traced to a lost connection with your Internet service provider.

Solutions

If you see a “failure to connect” or “no response” message or have otherwise determined that you have failed to connect, double check to make certain there are no physical problems.

First, check your cables and connections. If you use a dial-up modem, listen to make sure it produces the normal high-pitched dialing sound. If not, the problem could be a loose connection. Locate the phone cord that runs from the back of your computer to the phone jack, and then make sure that each end is plugged in snugly.

If you will don’t hear the expected dialing sound, check to make sure your phone cord is undamaged. If it seems worn, replace it with a new one. Other steps include making certain the line is plugged into the right port, and checking the phone jack by plugging the cord into a different jack. If you hear the dialing sound after any of these steps, you have made a successful connection.

Connection problems may be more common with dial-up modems than with broadband connections, but the latter are also dependent on physical connections. A loose wire or poorly connected cable can easily be problematic. Sometimes a glitch occurs that can be best addressed by repeating portions of the initial set-up process. A simple fix touted by Verizon technical service reps for some DSL (digital subscriber line) customers is to disconnect the three lines from the back of the modem and then reconnect them in a specified order. When this action is taken, the online connection is immediately regained.

If you are online but keep getting bumped off, the lost connection can be the result of an unintended software command. In Outlook Express, for example, you will find the command “Hang up when finished.” If the box in front of this phrase is checked, the connection will automatically be severed each time you send or download e-mail. Sometimes a misdirected click of your mouse will cause you to place a check in the box even though you do not realize it. Simply click on the check mark to make it disappear, and the hang-ups will cease.

These 2 common e-mail problems are quite easy to determine and when rectified will make your emailing experience more enjoyable.