CCNA Certification

CCNA, CCNP, CCIE Certification News

CCNA: Static Routing Tutorial

In studying for your CCNA exam and preparing to earn this valuable certification, you may be tempted to spend little time studying static routing and head right for the more exciting dynamic routing protocols like RIP, EIGRP, and OSPF.

This is an understandable mistake, but still a mistake. Static routing is not complicated, but it’s an important topic on the CCNA exam and a valuable skill for real-world networking.

To create static routes on a Cisco router, you use the ip route command followed by the destination network, network mask, and either the next-hop IP address or the local exit interface. It’s vital to keep that last part in mind – you’re either configuring the IP address of the downstream router, or the interface on the local router that will serve as the exit interface.

Let’s say your local router has a serial0 interface with an IP address of 200.1.1.1/30, and the downstream router that will be the next hop will receive packets on its serial1 interface with an IP address of 200.1.1.2/30. The static route will be for packets destined for the 172.10.1.0 network. Either of the following ip route statements would be correct.

R1(config)#ip route 172.10.1.0 255.255.255.0 200.1.1.2 (next-hop IP address)

OR

R1(config)#ip route 172.10.1.0 255.255.255.0 serial0 ( local exit interface)

You can also write a static route that matches only one destination. This is a host route, and has 255.255.255.255 for a mask. If the above static routes should only be used to send packets to 172.10.1.1., the following commands would do the job.

R1(config)#ip route 172.10.1.1 255.255.255.255 200.1.1.2 (next-hop IP address)

OR

R1(config)#ip route 172.10.1.1 255.255.255.255 serial0 ( local exit interface)

Finally, a default static route serves as a gateway of last resort. If there are no matches for a destination in the routing table, the default route will be used. Default routes use all zeroes for both the destination and mask, and again a next-hop IP address or local exit interface can be used.

R1(config)#ip route 0.0.0.0 0.0.0.0 200.1.1.2 (next-hop IP address)

OR

R1(config)#ip route 0.0.0.0 0.0.0.0 serial0 ( local exit interface)

IP route statements seem simple enough, but the details regarding the next-hop IP address, the local exit interface, default static routes, and the syntax of the command are vital for success on CCNA exam day and in the real world.

February 27, 2006 Posted by | CCNA | Leave a comment

CCNA Certification: The Different Kinds Of Switching

When you´re studying for your CCNA exam, whether you´re taking the Intro-ICND path or the single-exam path, you´re quickly introduced to the fact that switching occurs at Layer 2 of the OSI model.

No problem there, but then other terms involving switching are thrown in, and some of them can be more than a little confusing. What is “cell switching”? What is “circuit switching”? Most confusing of all, how can you have “packet switching”? Packets are found at Layer 3, but switching occurs at Layer 2. How can packets be switched?

Relax! As you´ll see in this article, the terms aren´t that hard to keep straight. Packet switching, for example, describes a protocol that divides a message into packets before they´re sent. The packets are then sent individually, and may take different paths to the same destination. Once the packets arrive at the final destination, they are reassembled.

Frame switching follows the same process, but at a different layer of the OSI model. When the protocol runs at Layer 2 rather than Layer 3, the process is referred to as frame switching.

Cell switching also does much the same thing, but as the name implies, the device in use is a cell switch. Cell-switched packets are fixed in length. ATM is a popular cell-switching technology.

The process of circuit switching is just a bit different, in that the process of setting up the circuit itself is part of the process. The channel is set up between two parties, data is transmitted, and the channel is then torn down. The circuit-switching technology most familiar to CCNA candidates is ISDN.

Don´t let these terms confuse you. The four different terms are describing much the same process. The main difference is that they are occurring at different levels of the OSI model, and using a different transport method to get the data where it needs to go.

February 13, 2006 Posted by | CCNA | Leave a comment

CCNA Certification: Defining Broadcast Domains

When you’re studying to pass the CCNA exam and earn your certification, you’re introduced to a great many terms that are either totally new to you or seem familiar, but you’re not quite sure what they are. The term “broadcast domain” falls into the latter category for many CCNA candidates.

A broadcast domain is simply the group of end hosts that will receive a broadcast sent out by a given host. For example, if there are ten host devices connected to a switch and one of them sends a broadcast, the other nine devices will receive the broadcast. All of those devices are in the same broadcast domain.

Of course, we probably don’t want every device in a network receiving every single broadcast sent out by any other device in the network! This is why we need to know what devices can create multiple, smaller broadcast domains. Doing so allows us to limit the broadcasts traveling around our network – and you might be surprised how much traffic on some networks consists of unnecessary broadcasts.

Using the OSI model, we find devices such as hubs and repeaters at Layer One. This is the Physical layer, and devices at this layer have no effect on broadcast domains.

At Layer Two, we’ve got switches and bridges. By default, a switch has no effect on broadcast domains; CCNA candidates know that a switch will forward a broadcast out every single port on that switch except the one upon which it was received. However, Cisco switches allow the creation of Virtual Local Area Networks, or VLANs, that are logical segments of the network. A broadcast sent by one host in a VLAN will not be forwarded out every other port on the switch. That broadcast will be forwarded only out ports that are members of the same VLAN as the host device that sent it.

The good news is that broadcast traffic will not be forwarded between VLANs. The bad news is that no inter-VLAN traffic at all is allowed by default! You may actually want this in some cases, but generally you’re going to want inter-VLAN traffic. This requires the use of a router or other Layer 3 device such as a Layer 3 Switch. (Layer 3 Switches are becoming more popular every day. Basically, it’s a switch that can also run routing protocols. These switches are not tested on the CCNA exam.)

That router we just talked about also defines broadcast domains. Routers do not forward broadcasts, so broadcast domains are defined by routers with no additional configuration.

Knowing how broadcasts travel across your network, and how they can be controlled, is an important part of being a CCNA and of being a superior network administrator. Best of luck to you in both of these pursuits!

February 13, 2006 Posted by | CCNA | Leave a comment

The Path To Follow After Earning Your CCNA

Once you earn your CCNA certification, you´ve got quite a few exciting choices ahead of you!

The majority of CCNAs go on to pursue another Cisco certification, and this is a wise decision. The more you know, the more valuable you are in today´s IT market.

A question I´m often asked by new CCNAs is “Which certification should I go after next?” Often, these new CCNAs have their eye on the Cisco Certified Security Professional (CCSP) certification. While adding a security certification to your resume is an excellent idea, I strongly recommend that new CCNAs acquire their Cisco Certified Network Professional (CCNP) certification before pursuing their security certifications. The CCNP requires you to pass three or four exams (depending on the path you choose) that will demand a further mastery of some subjects you studies to earn your CCNA as well as several important topics that you haven’t seen yet.

The CCNP builds on the foundation of networking knowledge you built when you earned your CCNA, and your CCNP study will add greatly to your skills and resume. There are some common technologies that you´ll see in many networks – BGP and route redistribution among them – that you don´t learn about in your CCNA studies. By pursuing your CCNP, you´ll also learn much more about OSPF, switching, and refine your troubleshooting skills. These are skills that will pay off in your current job as well as any future job hunting you do.

I know that security is the hot topic of the day, and with good reason. But to be a well-rounded networking engineer, you need to understand BGP, route redistribution, complex route summarization scenarios, and many other topics that earning the CCNP will help you understand. And besides, the security certifications will definitely be there when you´re done earning your CCNP!

February 13, 2006 Posted by | CCNA | Leave a comment

CCNA / CCNP: Deciphering Ping Output

As you study for your CCNA and CCNP exams, particularly if you’re getting hands-on practice in your home lab or rack rental service, you’re going to be sending a lot of pings. As a CCNA or CCNP candidate, you know that five exclamation points (!!!!!) as a ping return indicates that you have IP connectivity to the remote destination. Five periods (…..) indicates that you do not have that connectivity.

It’s not enough to know that you don’t have IP connectivity to the remote device, you’ve got to know why. Ping is a great first step to network troubleshooting, but the results are quite limited. As a CCNA and CCNP, you’ve got to know how to diagnose the problem and resolve it. Just looking at the routing table is not enough – a high-powered Cisco debug, debug ip packet, can often show you exactly where the problem is.

WARNING: debug ip packet should not be run on any production router without understanding the effect of this command on your router. This command results in a lot of output and can actually lock up a router.

In this case, we’ll run the command on a home lab router that cannot ping 22.2.2.2. The debug will be turned on and another ping sent.

R1#debug ip packet
IP packet debugging is on
R1#ping 22.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 22.2.2.2, timeout is 2 seconds:
3d23h: IP: s=1.1.1.1 (local), d=22.2.2.2, len 100, unroutable.
R1#undebug all
All possible debugging has been turned off

I’ve edited this output for clarity; the important word is “unroutable”. This indicates that the packet is not leaving the router because there is no match in the routing table for this destination. We’ll configure a static default route and send the ping again.

R1#ping 22.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 22.2.2.2, timeout is 2 seconds:
U.U.U
Success rate is 0 percent (0/5)

That output may surprise those of you who are used to getting five of the same symbol back whenever you send a ping. We got three “U”s back along with two periods. We’ll now run debug ip packet and send the ping again.

R1#debug ip packet
IP packet debugging is on
R1#ping 22.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 22.2.2.2, timeout is 2 seconds:
3d23h: IP: s=172.12.123.1 (local), d=22.2.2.2 (Serial0), len 100, sending
R1#traceroute 22.2.2.2
Type escape sequence to abort.
Tracing the route to 22.2.2.2
1 172.12.123.2 36 msec 36 msec 36 msec
2 172.12.123.2 !H

February 7, 2006 Posted by | CCNA, CCNP | Leave a comment

How To Pass The CCNP: Some Final Exam Tips

CCNP candidates have taken a Cisco exam before, but remind yourself of these exam rules:

Make sure to bring your wallet or purse.   You cannot take the exam without proper identification.   You’ll probably be asked for two forms of ID, one of which must be a picture ID.
Most testing centers hand you a dry erase board and a marker.  Make sure that the marker has a fine point; when you’re answering subnetting questions or performing a hexadecimal-to-binary conversion, that will come in handy.

Despite the best efforts of VUE and Prometric, some testing center rooms are afterthoughts.  I strongly advise that if you’re taking your exam at a technical school, ask to see the testing room BEFORE you sign up for the exam.  If it looks like a converted broom closet, it probably is.  Those rooms also tend to be right next to classrooms, which can result in distracting noise during your exam.

If your testing center specializes in giving computer-based exams rather than classes, you’re probably in good shape.  Again, feel free to drop by the testing center before your exam to take a peek at the testing room.  Most testing rooms have a window that employees use to keep an eye on testers, and you should be able to take a peek through the window.

When you take a Cisco exam, you’ll first be presented with a survey.  The survey consists of 10 – 20 questions asking about your background, preparation methods, and comfort level with different technologies.   This is a good time to catch your breath before starting the exam.  The survey will only take about five minutes, and this time does not count against your exam time.

You’ll then be presented with an exam tutorial, showing you how to answer the different types of questions Cisco may ask.  While most of these questions types are common sense (multiple choice, single answer, fill-in-the-blank), I strongly urge you to pay special attention to the router simulator question tutorial.

The simulator questions carry more weight than the other questions; indeed, it’s almost impossible to pass the CCNP exams if you totally miss the simulator questions. While the interface for these exams is intuitive, sometimes students who fail their exam complain that they were not given enough information to answer the question.  The real problem is that they didn’t look in the right place for that information.  It’s not hidden, but spend a few minutes with the tutorial and do not go forward until you’re comfortable with the simulator interface.

Finally, the exam starts!   Remember, you’re not being asked anything you don’t know.    If you have prepared correctly with the right tools, you’ll have a passing grade on your screen before you know it.

Speaking of that grade, you’ll be presented with it about five seconds after you answer the final question.   Cisco exams no longer allow CCNA and CCNP candidates to go back once a question is answered, so be prepared for that.

February 2, 2006 Posted by | CCNP | 1 Comment

How To Pass The CCNP: The Day Of The Exam

Exam Day!
Today, all the planning and work you’ve done for your CCNP exam pays off. You wake up confident and ready to go, because you’ve followed these steps and you know passing the exam is a foregone conclusion.

There are still things you can do to maximize your chances of success!

Show up on time. Yes, I know everyone says that. The testing center wants you there 30 minutes early. So why do so many candidates show up late, or in a rush? Again, if you have a morning exam appointment, make sure to allow for rush hour traffic.

Use the headphones. Most candidates in the room with you understand that they should be quiet. Sadly, not all of them do. Smacking gum, mumbling to themselves (loud enough for you to hear, though), and other little noises can really get on your nerves in what is already a pressure situation. In one particular testing center I use, the door to the testing room has one setting: “Slam!”.

Luckily, that center also has a headset hanging at every testing station. Call ahead to see if yours does. Some centers have them but don’t leave them at the testing stations. Wearing headphones during the exam is a great way to increase your powers of concentration. They allow you to block out all noise and annoyances, and do what you came to do – pass the exam.

Prepare for the “WHAT??” question. No matter how well-prepared you are, there may be one question on any Cisco exam that just stuns you. It might be off-topic, in your opinion; it may be a question that would take 10 of your remaining 15 minutes to answer; it might be a question that you don’t even know how to begin answering. (It could also be a beta question. Beta questions don’t count toward your exam score, but you’re also not told when a question is a beta!) I have talked with Cisco exam candidates who got to such a question and were obviously so thrown off that they didn’t do well on any of the remaining questions, either.

There is only one thing to do in this situation: shrug it off. Compare yourself to a major-league pitcher. If he gives up a home run, he can’t dwell on it; he’s got to face another batter. Cornerbacks in football face the same problem; if they give up a long TD pass, they can’t spend the next 20 minutes thinking about it. They have to shrug it off and be ready for the next play.

Don’t worry about getting a perfect score on the exam. Your concern is passing. If you get a question that seems ridiculous, unsolvable, or out of place, forget about it. It’s done. Move on to the next question and nail it.

Finish with a flourish. Ten questions from the end of your exam, take a 15-to-30 second break. You can’t walk around the testing room, but you can stand and stretch. By this point in the exam, candidates tend to be a little mentally tired. Maybe you’re still thinking about the “WHAT??” question. Don’t worry about the questions you’ve already answered – they’re done. Take a deep breath, remember why you’re there — to pass this exam — and sit back down and nail the last ten questions to the wall.

There is one final piece of advice I’d like to give you for exam day:

BE AGGRESSIVE.

You’re in that testing room for one reason: to PASS.

Occasionally I hear someone say that they’re taking an exam “just to see what it’s like”. That’s not a winning attitude. You’re not there to see what it’s like; you’re there to pass so you don’t have to see it again.

Would you work on a router or switch with the attitude of “let’s just see what happens”? Not on my network. Go in the testing room with an aggressive attitude. You’ve planned; you’ve studied; you’ve sacrificed. You’re ready to seize your destiny and pass the exam.

We play the game to win the game.

We take the exam to pass the exam.

And from someone who’s been there – there is no feeling in the world like seeing “PASS” on that computer screen!

Next: How To Pass The CCNP: Some Final Exam Tips

February 2, 2006 Posted by | CCNP | Leave a comment

How To Pass The CCNP: The Big Day Approaches

As exam day nears, you know you are on your way to success because you have already completed these steps:

  1. You decided to succeed.
  2. You decided on your exam path.
  3. You scheduled your exam.
  4. You created your study plan.
  5. You tracked your UNINTERRUPTED study time.
  6. You kept your goals away from negative influences.
  7. You balanced your study between books, practice exams, flash cards, and lab time.

At this point, some CCNP candidates are panicking. They start “cramming”, hoping they can jam all that information into their heads in the last minute.

This is a study technique that needs to be left behind when you leave high school. Cramming for exams is for teenagers. You’re a professional, in a professional field. You do not cram, because you don’t have to. You made a plan and stuck to it.

Now as we approach exam day, use these techniques to maximize your effort.

First, get lots of rest. LOTS of rest. A well-rested candidate is a successful candidate.

Second, if you are not familiar with the location of the testing center, drive to it several days before the exam. The last thing you want to do is drive around like a mad person the day of your exam, trying to find the testing center. (Or, as happened to a friend of mine that the testing center had moved to the other side of town!)

If you have a morning appointment, make sure you allow for rush hour traffic patterns. There’s one testing center in my city that takes 15 minutes for me to get to, except for one hour in the morning – if I go then, it takes 40 minutes. Allow for rush hour!

Do NOT rely on MapQuest or any other “driving directions” website the morning of the exam. They’ve been known to be wrong. (Trust me on this.) Call the center and ask for directions. Many testing centers have directions to the center on their website, but it’s always best to call.

Mentally rehearse your success. See yourself passing the exam, because that is exactly what you are going to do.

Finally, take a practice exam the same way you’ll take the real exam. Time yourself, use a pen and paper, and use only 40 – 50 questions.

(By the way – there is no scientific calculator available to Cisco certification candidates in the exam room. You have to know how to perform conversions involving hexadecimal, decimal, and binary numbers. Get as much practice on this as you can. CCNP exams place an emphasis on VLSM.)

Next: How To Pass The CCNP: The Day Of The Exam

February 2, 2006 Posted by | CCNP | 1 Comment

How To Pass The CCNP: Budgeting Your Study Time

CCNP study consists of time spent studying book, taking practice exams, and spending time working with Cisco equipment. Let’s take a look at these three categories.

Book Study

I’ve never understood why some people (usually the trolls we were talking about earlier, or a close relative) talk about book study like it’s a bad thing. “You can’t learn about technology from books”, they say.

What a load of manure THAT is. You have to learn theory before you can understand how a router, switch, or protocol operates. The best way to learn theory is to read a good book, preferably more than once!

Make sure the book you choose has sufficient depth for the CCNP exams. Reviews on amazon.com can give you an idea of how well-suited a book is for your CCNP study, although you should be wary of “professional reviewers” on that site. They tend not to be technical people; why they’re reviewing technical books, I don’t know.

Practice Exams

Practice exams are good in moderation, but don’t use them as your main focus of study. On occasion, I’m asked for CCNA or CCNP study tips by candidates who have taken the exams and haven’t passed yet. I ask them what they’re doing to prepare, and they reel off a list of practice exams they’ve purchased.

Don’t fall into this trap. Practice exams are fine if used as a readiness check, but some candidates just take them over and over again, which renders the basically useless. Combine that with the fact that some practice exams cost $200 and up! That’s money you’d be better off spending on real Cisco equipment.

Lab Time On Real Cisco Equipment

Again, I speak from experience: This is the most important part of getting your CCNP, excelling in the real world, and laying the foundation for your CCIE studies.

Even if you have no interest in the CCIE, you’ve GOT to have real hands-on knowledge for the CCNP exams. The only way to develop troubleshooting skills is to work on the real deal, not on “router simulators”.

A simulator is a software program pretending to be a router. You’re not interested in being a “pretend” CCNP; you want to be a real CCNP with real knowledge of routers and switches.

Besides, as someone who’s done plenty of screwing up in a lab J, I can tell you… you do your best learning when you screw something up and you have to fix it yourself.

That’s how you develop your troubleshooting skills! You can read about all the show and debug commands you want, and play with them on simulators, but you don’t really understand how things work on Cisco equipment until you’re working with the real thing.

This is true at every level of the Cisco learning pyramid. I can show you the show ip protocols output, or what a BGP routing table looks like, and you might remember it for a little while. But when you use it for real, you WILL remember it.

If you prefer not to make that investment, I have the world’s only rack rental service that is designed and priced just for CCNA and CCNP candidates. I invite you to visit the website to learn more about this unique training opportunity.

One way or the other, there is no better way to develop the self-confidence and troubleshooting skills that you must have to pass the CCNP exams and excel in the real world than to configure real Cisco routers and switches.

Working with real Cisco equipment will help you get past what I call “simulator question anxiety”. If you spend any time on CCNP internet forums, you’ll see discussion after discussion about these exam questions. (Reminder: It’s an NDA violation to discuss Cisco exam questions.) To a certain point, this concern is justified; the simulator questions carry more weight on your exams than any other question, and you’ve got to get them right or you will most likely fail the exam.

There’s no reason to be anxious about them if you’re prepared, though! You don’t want to be the person who walks into the exam room in terror of these questions. You want to be the person who walks in confident in their ability to perform any CCNP-level task. The only way to get there is to work with real Cisco equipment.

Next: How To Pass The CCNP: The Big Day Approaches

February 2, 2006 Posted by | CCNP | 1 Comment

How To Pass The CCNP: Carrying Out Your Study Plan

You’ve scheduled your exam; you’ve created a document to track your study time; you’ve planned exactly when you’re going to study. Now this plan must be carried out, without exception.

What exceptions? Cell phones. Instant messages. Televisions. Significant others. The list can go on and on.

It’s one thing to have a plan, and it’s an important thing. Now you’ve got to make sure you carry it out to its fullest potential.

That’s easy to say until you’re studying and a friend calls, or you remember that TV show you really wanted to watch is on tonight, or a friend sends you an instant message while you’re studying for your exam.

TV will be there when you’re done studying. Your significant other will be there when you’re done studying. And believe it or not, you do not cease to exist when you turn your cell phone off.

Turn the phone off, turn your TV off, turn your pager off, turn your instant messenger service off. The world can survive without communicating with you for an hour or two. Remember, it’s better to have 90 minutes of great study than 180 minutes of constantly interrupted study.

Next: How To Pass The CCNP: Budgeting Your Study Time

February 2, 2006 Posted by | CCNP | 1 Comment