Monday, March 06, 2006

 

Cisco CCNP / BSCI Exam Tutorial: Route Summarization By Chris Bryant

Preparing to pass the BSCI exam and earn your Cisco CCNP? Route summarization is just one of the many skills you'll have to master in order to earn your CCNP. Whether it's RIP version 2, OSPF, or EIGRP, the BSCI exam will demand that you can flawlessly configure route summarization.

Route summarization isn't just important for the BSCI exam. It's a valuable skill to have in the real world as well. Correctly summarizing routes can lead to smaller routing tables that are still able to route packets accurately - what I like to call "concise and complete" routing tables.

The first skill you've got to have in order to work with route summarization is binary math more specifically, you must be able to take multiple routes and come up with both a summary route and mask to advertise to downstream routers. Given the networks 100.16.0.0 /16, 100.17.0.0 /16, 100.18.0.0 /16, and 100.19.0.0 /16, could you quickly come up with both the summary address and mask? All you need to do is break the four network numbers down into binary strings. We know the last two octets will all convert to the binary string 00000000, so in this article we'll only illustrate how to convert the first and second octet from decimal to binary.

100 16 = 01100100 00010000

100 17 = 01100100 00010001

100 18 = 01100100 00010010

100 19 = 01100100 00010011

To come up with the summary route, just work from left to right and draw a line where the four networks no longer have a bit in common. For these four networks, that point comes between the 14th and 15th bits. This leaves us with this string: 01100100 000100xx. All you need to do is convert that string back to decimal, which gives us 100 for the first octet and 16 for the second. (The two x values are bits on the right side of the line, which aren't used in calculating the summary route.) Since we know that zero is the value for the last two octets, the resulting summary network number is 100.16.0.0.

But we're not done! We now have to come up with the summary mask to advertise along with the summary route. To arrive at the summary route, write out a mask in binary with a "1" for every bit to the left of the line we drew previously, and a "0" for every bit to the right. That gives us the following string:

11111111 11111100 00000000 00000000

Converting that to dotted decimal, we arrive at the summary mask 255.252.0.0. The correct summary network and mask to advertise are 100.16.0.0 252.0.0.0.

For the BSCI exam, emphasis is put on knowing how to advertise these summary routes in RIPv2, EIGRP, and OSPF. For RIP v2 and EIGRP, route summarization happens at the interface level - it's not configured under the protocol. On the interface that should advertise the summary route, use the command "ip summary-address". Here are examples of how the above summary route would be configured on ethernet0 in both RIPv2 and EIGRP.

R1(config-if)#ip summary-address rip 100.16.0.0 255.252.0.0

R1(config-if)#ip summary-address eigrp 100 100.16.0.0 255.252.0.0

The main difference between the two is that the EIGRP command must specify the AS number - that's what the "100" is in the middle of the EIGRP command. Since RIPv2 does not use AS numbers, there's no additional value needed in the configuration.

For OSPF, the commands differ. If you're configuring inter-area route summarization, use the "area range" command. The number following "area" is the area containing the routes being summarized, not the area receiving the summary.

R1(config)#router ospf 1

R1(config-router)#area 1 range 100.16.0.0 255.252.0.0

If you are summarizing routes that are being redistributed into OSPF, use the summary-address command under the OSPF routing process on the ASBR.

R1(config)#router ospf 1

R1(config-router)#summary-address 100.16.0.0 255.252.0.0

I speak from experience when I tell you that practice makes perfect on the BSCI exam, especially with binary and summarization questions. The great thing about these questions is that there are no grey areas with these questions - you either know how to do it or you don't. And with practice and an eye for detail, you can master these skills, pass the exam, and become a CCNP. Here's to your success on these tough Cisco certification

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free CCNA and CCNP tutorials! Pass Pass the CCNA exam with Chris Bryant!



Thursday, February 16, 2006

 

How to pass CCNA: 6 Steps to Success By Vanja Buric

CCNA is one of the most respected Associate level Certification in the world today.
Getting a CCNA will definitely help you to get a better job or at least get your foot into Professional Networking Field. When you meet a person that has CCNA degree you will notice that he or she knows something about Networking.
This article will describe and give you some tips on how to achieve CCNA.
I did it so can you, so lets get started.

· 1. Getting ready mentally:

First thing you need to do is mentally prepare your self. What I mean by that is that you have to seriously think about on why are you getting CCNA and why do you want to be CCNA certified. You have to firmly decide and believe that you will get CCNA within next 3-6 months or so.
Try to budget your study time well. If you a very social person (like me) you will have to give up some of your social time for the next couple of months.
Your friends and family will understand. Trust me: it is well worth it. Once you get that cert you can make up for the lost social time.

· 2. Getting the right study material:

Second thing you need to do is to get proper study material.
There is lot of controversy around this and some people go overboard with study guides, books, simulators and such.
I believe that two Cisco Press books INTR and ICND by Wendell Odom are enough as far as the books go. They are really well written and easy to follow. So sign up at http://www.ciscopress.com and get those two books. Make sure you got the latest version.
You will also want to get some kind of a simulator that will let you practice commands and that will also build up your confidence.
You can buy real equipment but that could get expensive. I highly recommend that you become member of Cisco Certification forum.
Forum is huge and you will get lot of helpful answers, tips and advices pretty quick. (I know I did)

· 3. Approach and diving deep:

There are many different approaches to studying from books but I will tell you about mine. This step will take the most of your studying time.
-Before you even start reading any of the books I suggest learning binary math (really easy) and subnetting so you can do it in your sleep.
http//www.learntosubnet.com is excellent resource. -read both books casually once from front to cover (make sure you cover introduction and practice questions too). This will give you good overview.
-Install both CD’s that came with books and practices some of the questions. Don’t worry if you get lot of them wrong.
-Now, you will ready both books again but this time you will have to read it to truly understand the concept and how things work. Master one chapter and do questions from just that chapter until you sick of it. Then move to the next chapter.
-Once you mastered all chapters do lot of questions and labexercises. Those two CD’s will give you ability to do that.

4. Schedule the test:

You’re not done yet with studying but it is really good to schedule the test after you completed step 3 in this article. Here is why:
If you schedule the test a month in advance right after you completed step 3, you won’t be able to slack and make excuses not to study hard until tests and it is also good to give your self a headline. I have seen people working on their CCNA for 2 years. They master one or two chapters, then they rest for 2 two months and right when they think they are ready for the next chapter, they forget what they have learned in the first chapter.

5. Read both books one more time to refresh.

This is optional, but I highly recommend reading the both books one more time. If you read both books in a three week that will give you one more week before the test to cram which is subject of the next step.
So by now you should’ve read both books three times over. I also suggest re-reading questions and answers from both books one more time.

6. Cram, Cram and Cram -This is the last part of your study and there is no turning back.

Deadline is hanging around your neck like a noose. You should cram Q&A for no more then 10 days before you take the test.
At this point it is really important that you get fresh and different questions then those included with your CD’s. Some people claims that brain dumps or Q&A are bad and evil. I tend to disagree with that. At this point you already firmly grasped the whole CCNA concept and Q&A will only help you. So get some Q&A exam question and cram, cram and cram them for a week.
Don’t use books or CD’s anymore. There is no looking back. No worries, material from the books will return to you at the right time.
-Don’t do any studying a night or a day before the test. Go out with your wife or significant other to a dinner and a movie. Relax. It is very important to relax and get a good night sleep since one of those testing boots could really be intimidating. If you did all the steps above and read books with intention to understand the topics and how stuff works (no pun intended), and not just to pass the test you should be more then ready by now.
We came to an end of this short tutorial. I hope this article give you at least some ideas on how to approach studying for CCNA.
If you fail CCNA first time, don’t get discouraged. You will have more knowledge and confidence when you attempt it the next time then the person who passed it on the first try. Whatever approach you take I wish you good luck and prosper career.
Vanja Buric is Network Engineer, and works for Charter Communication Business Engineering Department,
and also owner of the http://www.vanjaburic.com website, where you can get latest networking news, articles,tips, free e-Books, virus alerts and lot more… as well as purchase IT Exam study guides.

Sunday, February 12, 2006

 

Cisco Certification: The "Secret" Key To Getting Your CCNA And CCNP

Whether you're working on your CCNA or CCNP, Cisco certification exams are the most demanding computer certification exams in the IT field. Cisco exams are not a test of memorization, they're a test of your analytical skills. You'll need to look at configurations and console output and analyze them to identify problems and answer detailed questions. To pass these demanding exams, you've got to truly understand how Cisco routers and switches operate - and the key to doing so is right in front of you.
The debug command.
Of course, there is no single "debug" command. Using IOS Help, you can quickly see that there are hundreds of these debugs, and I want to mention immediately that you should never practice these commands on a production router. This is one major reason you need to get some hands-on experience with Cisco products in a home lab or rack rental. No software program or "simulator" is going to give you the debug practice you need.
Now, why am I so insistent that you use debugs? Because that's how you actually see what's going on. It's not enough to type a frame relay LMI command, you have to be able to see the LMIs being exchanged with "debug frame lmi". You don't want to just type a few network numbers in after enabling RIP, you want to see the routes being advertised along with their metrics with "debug ip rip". The list goes on and on.
By using debugs as part of your CCNA and CCNP studies, you're going beyond just memorizing commands and thinking you understand everything that's happening when you enter a command or two. You move to a higher level of understanding how routers, switches, and protocols work -- and that is the true goal of earning your CCNA and CCNP.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and BSCI tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages.
For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, visit the website and download your free copies!

This page is powered by Blogger. Isn't yours?