Learning Cisco

Learning Cisco – Getting Started.

This is a guide I have put together to help you get started on learning, and an opening to a great path of becoming an IT/network professional. This is mainly covering how to get started on obtaining your certifications from Cisco starting with the CCENT/CCNA.
I do know some of this stuff from either personal experience, as a general rule, forums, other’s experience, official rules, and from taking the CCNA myself.

First things first. I want to you to know, there are WRONG paths out there, wrong ways of learning, that will no doubt, give you a very rocky start to your journey to IT greatness. I want to first clear up misconceptions, misunderstandings, and myths that others may have queries about:

  1. DON’T USE BRAINDUMPS. – 99% of the time they do not work. And brain dumps certainly will not help you at a job. They will make you sound stupid when talking about networking in the real world to real professionals. Getting Cisco certified is about knowing and understanding networking like a second nature. If an employer sees that you cannot not do any structured troubleshooting, and just know theoretical networking, they will show you the door. Cisco Certifications are not about memorizing terms and remembering what acronyms, names, and concepts they relate to. They expect you to know networking inside and out, and they will damn well test you on it. Plus, they are down right cheating and you can probably spend about a month going through them and just bomb your tests.
  2. !!!-DO NOT PRACTICE  ON REAL PRODUCTION NETWORKS-!!!!. – DEBUGS ESPECIALLY, turning features on and off, re-converging networks, clearing routing tables, stopping and starting processes, changing parameters, IP addresses, duplex, messing with STP, purposely creating routing/switching loops, messing with ACLs and NAT, etc, etc. DO NOT TOUCH PRODUCTION NETWORKS. If you are already working with one, and you do any of this, I guarantee, you will be fired, arrested, killed, shot, stabbed, stoned, severely beaten, set on fire, dragged across a rocky desert plane by a truck, pushed in front of a train, tied to railroad tracks, drowned, electrocuted, thrown off a building, hit by a car, or anything else you could use your imagination to come up with a terrible way to die. This is why you need to setup a home lab, or use a classroom lab, or a simulator. There you can do ANYTHING you want to without the threat of a boss that will disembowel you with a plastic butter-knife. You will not only cost that company big loads of money, lost production time, cause blood pressures to rise and tempers to flare, but they will probably find a way to get you arrested and have your ass thrown in jail. Its their network, use your own practice one. This is exactly what its there for and you can break/fix/mess with it as many times and as much as you want. Company networks are there to make money, you are there to make it work, that is the whole idea of this certification.
  3. Don’t think knowing just networking concepts and theories is the be all, end all of these certs.  – There is far more to Cisco certs than just these. There is troubleshooting logic involved, understanding the uses of the technology, where, when, how, and why you should implement it.
  4. Don’t get used to subnet calculators. – Yeah they’re nice tools for when you’re actually on the job, but when you’re learning, you need to know how to subnet in your head. In seconds. I will have some great links down below on great places to practice subnetting and learn it. There are many different methods to learning it, find which one works quickest and best for YOU and stick to it. If you find counting in the powers of two and adding them to algorithms to calculate subnets, or if you like to use the BOOLEAN AND/OR method, or if you like to use a quick chart to match prefixes to their corresponding netmask numbers and their binary counterparts, or something else, that is fine. Learn it fluently and stick to it. Master it. Calculators, and subnet calculators DO NOT EXIST when you are studying for your certs. (They only exist when you are trying to check answers to see if you subnetted right, other than that, no, don’t even think about using them.) Learn to count by 1, 2, 4, 8, 16, 32, 64, and 128.
  5. Don’t skim on ANY material. – When you think you know it, you need to be absolutely, positively, I-can-do-this-in-my-sleep, sure. When you’re reading something, or watching a video, don’t think to yourself “oh I know this, I shouldn’t have to worry too much about this, I’ll just go on to the next thing”. Don’t. Even though you think you know it, you may be surprised to find things may be a bit different to what you thought they were. Also, even if you do know it, it NEVER hurts to review, and re-enforce your knowledge of a given topic. When you go to take your exams for the certifications, and you think you’re confident and ready for it, prepare to have that confidence crushed, as the exam takes your brain and stuffs it in a blender and hits the liquidizer button.
  6. Don’t always take other, non-official information sources seriously. – While there are some excellent websites and forums out there (like Networking-Forum.com for example 🙂 ), remember, if you are confused about a concept because you see conflicting information from different sources, look to Cisco’s Knowledge Base (use the search function on there) and verify it yourself. When you go asking around on good forums (again, like Networking-Forum.com), most of the gurus there will point you to Cisco’s website to verify. They will clear up things for you, and even make your understanding of theories and concepts better, but they’re not going to flat out take 2 hours and type out an explanation for you.
  7. Don’t go around forum to forum asking other people to do your homework. – Seriously, if you are in a networking class where there is an instructor who assigns homework, DO IT. Otherwise, why bother, you’re just wasting your money. What use is it if you’re not going to learn anything. Go fail the class rather than beg professionals on the internet to do your homework. This doesn’t mean you shouldn’t go on forums and get pointers, ideas, clarification, and understanding, after all, that is probably about 25% of how you’re going to learn in a lifetime IT career. But don’t get on there “lol hi guise, this problem says what algorithm duz EIGRP use to calculate routes? is it a b c or d?” First of all, you’re shooting yourself in the foot here, because you are learning nothing, go read the whole chapter about EIGRP again. Rather ask “so this question asks how a switch uses STP to close redundant links in a switched network and prevents switching loops. It does this by sending BPDUs right? It says in my book that it sends probes out and see if it gets them back, but is that what BPDUs are?”, more likely, you are going to get a far more clearer, and friendlier response, and most likely you’ll find the answer to the problem very shortly after you ask it.
  8. (Last but not least)DON’T GIVE UP. – Don’t get down if you fail your first test, or any cert test for that matter. I personally don’t even refer it to failing. I call it “not meeting Cisco’s expectations of knowledge and understanding”. You got an opportunity to get your feet wet and see what the test was like, what it demands of you. While all that knowledge is still swimming around in your head and fresh, take about a week or two, go back, review everything, redo all your labs, a once-over if you will, and go reschedule that test and kill it. You’ll probably find where your obvious mistakes were when taking test and that conecpt/theory will bond to your head like the time I glued my shirt to a table  because I accidentally wiped glue on my t-shirt and leaned forward and touched it to the table. (Seriously, that was not fun, that was an awesome shirt too and I was using Gorilla Grip because I was trying to fix something.) The next time you take that test, you will probably destroy it, and you will find you passed with a score well above the required.
  9. “TL;DR” – If you didn’t bother reading this guide, or hate reading, good luck to you I say. Studying for any complicated certifications such as the ones from Cisco require hours upon hours of reading. Sometimes you even find you have to read the same thing over and over. If you are not one for reading, you’re not going to get very far, and will most likely end up having a very disfigured knowledge of networking that will do no good on certification exams and in real world applications. Employers certainly will not like this at all. You will have mixed misunderstanding of concepts/theories/procedures and you might as well start from square one and go on a different path for a career. If you don’t like reading, well you better suck it up, if you choose this sort of path for a career, math and reading are going to hide in every dark corner and jump out at you when you least expect it. If you think you can get by learning for your CCNA from Audio Books or Watching Videos, you’re sadly mistaking.

Books, Videos, and Other Guides.

These are some books and learning material I have been using as well as helpful links for working on your own journey to being a Cisco Pro.

This is mostly only CCNA level material.

Sybex CCNA Cisco Certified Network Associate Study Guide – 5/5
This is a great detailed Textbook for the CCNA , you can also get his videos which in my opinion, go great with it. I actually learned how to subnet and how subnetting works from this book better than anywhere else.
This is written by Todd Lammle

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Cisco Press Official Cisco CCNA Guide: – 4/5
This is Cisco’s official published learning material, where all the material that must be covered in the CCNA is in here.
This is written by Wendell Odom.
Wendell Odom’s Blog

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CBT Nuggets CCNA Video Series by Jermey Cioara. 5/5
These are a great set of videos detailing everything you need to know in the CCNA that Cisco requires, and some lessons on real world applications. Not just for your certification exams. This guy is brilliant, and teaches you everything in a structured manner, and makes you understand complicated concepts better, and watching the videos a few times over will help you drill concepts into your head better. He also doesn’t sound like he is droning on and on like a professor at a college giving a lecture. He teaches like a corporate IT pro showing you how to do things over your shoulder at work. Kind of like you’ve taken an internship at a company and hes there just dedicating all his time to teach you things.

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Train Signal CCNA Video Series, and practice exams by Chris Bryant 5/5
Also known as “The Computer Certification Bulldog”, I would say he also makes a great CCNA series. The material he teaches in his videos are specific, and too the point. Each lesson covers concepts deeply, so you have to keep re-watching a few of his videos to pick up on certain concepts and thoeries. All the lessons are structured as well, divided into their own curriclums, CCENT and the CCNA (ICND1 and ICND2). He teaches like an instructor in a classroom, but you’re the only student, and leads you through lessons slowly and detailing concepts very well. As a bonus when you buy the material, included is an exam simulator, that covers the entire CCNA and contains quite a plethora of test questions.

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Cisco Official Online Networking Academy.
This is Cisco’s official online networking course. You can enroll in it usually by buying access to it from Cisco, or by enrolling in it via a networking curriculum you may be taking at a school, college or some sort of educational establishment that teaches with it. This is one of the best ways to learn, as it is made officially by Cisco themselves. Everything here will be accurate as well as everything you need to learn for your certifications. Its very straight-forward, and is like being in a classroom that documents everything to the T with detail. Some of it may not show up on your test, most of it will. If you enroll in this, there are lots of quizzes, tests, activities, and more information that will further enforce your learning. Your instructor will also assign tests for every module you go over. Everything is broken down into a neat structured set of modules. As a bonus, there is also a final test at the end of ICND1 and ICND2 you can take and if you score (I think, do not quote me on this) 75% or higher on it, you can get a test discount voucher for your test(s).
 


Lab Equipment and Simulators

There are two sides to Cisco Certifications. There is learning Networking Concepts, procedures, and theory. Then there is learning how to use the CLI Cisco named “IOS”, and the hardware.

Ethernet Cables:
In my opinion, don’t just learn how to make roll-over cables, or cross-over cables, or straight-through cables from a video, a book, or some pictures you found on the internet. DO THE REAL THING. Get some RJ-45 connectors and a spool of Cat5/6 and terminate some cables yourself.  A bag of 100 RJ-45s these days is like $29 at Radio Shack. Buy some, and practice. This you will definitely find, like the OSI and TCP/IP model, is an IT professional’s bread and butter. If you walk into a job interview for a NOC Tech for like $50k a year, and you can’t simply terminate a cable, the employer will say “yeah, uh, its been great, listen, we’ll give you a call, I, uhh… have a (last minute surprise) meeting to get to”, and obviously you won’t hear back from them. Ever.

One of the most important  parts of studying for your Cisco Certs (or just about any cert for that matter, be it Juniper, Microsoft, IBM, etc.) are labs. Learning the concept of networking from a textbook is just not enough. You need to be able to do the things you are required to know on Cisco hardware. And its no use just trying to memorize commands. You need to be proficient in Cisco’s IOS, because you will have to do things like this on the exam, and you are timed. If you are not proficient enough, you’ll find yourself taking too long on labs and run out of time. Cisco expects you to know it, and obviously an employer does to. DO NOT SKIMP ON LA BS. I cannot stress this enough. Sure you have access to IOS help, but if you’re trying to type out a command and are constantly using the “?” to find out what the correct syntax for your command should be, it is going to take you a long time. Also, sometimes its not always that clear in the first place and you need to learn how to input commands right. There are a lot of things around commands, and syntaxes are always in different orders. Especially ACLs, and NAT.

So you need to find yourself good hardware to practice on? Well, of course there is eBay, you can buy there.
Usually if you’re going with hardware, the best and most recommended setup is to get three routers and three switches.

An ideal EXAMPLE setup would be something like:
2x 2621xm
1x 3620
2x 2950-24 catalysts
1x Catalyst 3550

This way you can learn the ins and outs of STP, (root concepts) And you can play with NAT statements and ACLs all day long and run debugs for just about every kind of protocol/process and not have a boss that wants to cut your heart out with a butcher knife. Its also important, for the real world, to watch network convergence on real hardware. Something a router simulator will not show you as well. You can watch routing or switching loops in action. You can also learn what kind of overhead protocols have, which one uses less, which one uses more, and learn what effect they will have on the hardware. You can also mess with SSH/TFTP, completely barebone your router, change/delete your IOS, mess with all sorts of things, etc. There are some valuable things you can learn from real hardware that router sims won’t.

When you buy network hardware on eBay, they are usually used. Some people take good care of their equipment, some downright abuse it. Some sales are really great, some are total rip offs. If you intend to buy Cisco hardware new, you better have some really deep pockets. But you can skim by pretty cheap if you buy off people who are selling used. They might even be selling hardware because they used the stuff to study for their certifications. Most bundle kits out there are pretty much rip offs and should be avoided, but from time to time, I’ll even find a setup someone was once using to practice with.

Of course, if you buy used, you probably won’t receive any support from Cisco, and there won’t be any warranties, but that sure does beat buying a 2600 router for $50 rather than $3,000. If you want things like warranties, (such as NetSmart Agreements) and support, then prepare to keep that wallet open.

If you decide to buy hardware  off eBay, I HIGHLY SUGGEST you take a minute to read all this: Packetlife.net – Tips for buying Lab Gear on Ebay.

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So you may not have a lot of money to buy your hardware and accessories. Well, there is still a way, its not the best way, but you can still achieve lab practice and learn IOS with simulators. They are usually inexpensive or free and don’t require sophisticated hardware. These are two I usually use. Sometimes, for when you are doing more advanced things for your CCNP or CCIE, to get those, you probably have done most of the basic configurations hundreds and hundreds of times already, and you know them so well, you could do all of that with in your sleep. So you may just want to get a quick setup going so that you can get right to the meat of the concept/theory/feature you’re trying to practice with.

Cisco Packet Tracer: Usually you can get this software on the internet when you sign up for Cisco’s Online Networking Academy. It’s a neat, ready out-of-the-box network simulator you can use to lab with. You can find all sorts of labs online you can use this with. This is Cisco’s official software they give you to learn with. Packet Tracer does have another advantage that GNS3 doesn’t. You can’t emulate switches on GNS3. You need to be able to work on switches on the CCENT (or ICND1 portion of the CCNA). So I would maybe stick to this for when you need to go over Layer 2 switching. Its ok if you ask me, but personally, I have found a few technical inaccuracies, bugs, and limits with this software. For instance, sometimes networks don’t converge the way they’re supposed to. There are a few other things I have found:

  • There are limits when writing Access Control Lists, and NAT statements.
  • STP to RSTP convergence.
  • EIGRP Unequal Cost load balancing doesn’t work correctly.
  • Debugs are not available.

There are a few others, but some of the things I mentioned above aren’t even covered in the CCNA to begin with. Packet Tracer is good if you just want to get a feel for IOS and if you want to test out some configurations. Its great to cover the CCNA from head to toe (hence why Cisco gives it to you). It has everything required. PT is an out of the box ready to discover and learn with kind of application. It doesn’t require any configuration to get it working. It is also more user friendly than GNS3. Its down fall is you’re not using true Cisco IOS, rather, a methodical platform to emulate IOS in sort of a third party manner.

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GNS3/Dynamips – Now this is what I’m talking about. GNS3, the graphical front end to Dynamips, allows you to actually emulate Cisco IOS, using real IOS images, on virtual routers. This in my opinion is a very accurate simulator for learning. You load real IOS images you would normally use on a router, onto virtual platforms that your computer runs for you. You can then internetwork all these routers and they can communicate with one another just like they would in a real network. This is a great way to learn because using actual IOS means you’re going to run into some real world problems most likely, and you can learn how to troubleshoot them. Also, everything is really accurate, I mean, you’re using the real software, just not the hardware. Also, a lot of the limits you find in Packet Tracer are not found in GNS3.

With GNS3 you can even create and practice CCNP and CCIE labs, since you can use any image you can find on the internet. You can also do things, such as run your own internet connection, into your GNS3 topology! You can use other REAL computers, or PCs hosted on a VMWare server, or you can find software like vpcs to create virtual computers on your PC. There are lots of things you can do with GNS3/Dynamips that you can’t do with other simulation software. I have found in my own studies GNS3 is great, and an awesome tool to learn with.

You can download GNS3/Dynamips Here.
You can get a quick-start guide here.

This is great software, however, with all its greatness, there are downfalls to it as well.

  • There is one significant advantage that PT has over GNS3. You can’t emulate switches. In the CCENT portion of your CCNA, they cover Layer 2 switching quite heavily. You can emulate SWITCHING in GNS3, but you have to use a router with a switching module built in. This is ok to a point, but you don’t really get to work with the kind of properties an L2 switch is supposed to have. So if you really need to learn switching, its better to do it on PT. I would say GNS3 is definitely going to be better in later studies when you’re working with L3 networking topoligies.
  • It is not as user friendly as Packet Tracer is, and requires far more configuration. You might spend a good hour learning how to get it all up and running correctly so that you can actually start doing labs on it.
  • An even bigger downfall, is yes, it uses REAL Cisco IOS images, but because IOS images are the intellectual property of Cisco, they do not come with the software. So you have to go out and find the IOS images yourself. Finding them can be easy if you know where to look, however I will not be posting any links to any of the sources of these websites, or any source of that matter for obvious reason. All I can say is that Google is your friend. You can maybe see if you can contact Cisco and they may be able to send you old IOS images or perhaps purchase some.
  • Running multiple routers on GNS3 can start to put strain on your PC as they work as individual machines, and your PC tries to do exactly what a bunch of routers actually do. This of course will cause your CPU utilization to go way up, and will use lots of resources. PCs with Intel Quad Core Processors or AMD Quad Core Processors, or fast Dual Cores, will work well with this program, however, as you create a larger, more complex topologies, it can even bog down fast processors. Luckily, however, there is an option built into the software to help with this problem called “setting an idle pc value”. This is all documented in their quick-start guide.

Overall it’s great software, its free, its opensource, it has it’s drawbacks, so it will come time to decide whats best for you. Great technical accuracy, but not user friendly? Or User-friendly, ready to use out of the box, but not a true IOS?


You will probably also want to check these out:

Useful Links, Information Sources, Professional Blogs, and Forums.

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2 responses to “Learning Cisco

  1. Pingback: Your Guide to starting your own Cisco Journey. | Third Layer

  2. Great guide! And so many truth in there, the path I’ve followed so far is the one described here.
    Also: nice information about making the Ethernet cables yourself. It would be silly if you stand in front of an employer with a CCNA/CCNP and have never made a cable in your life.

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