Cisco CCNA Certification: Don't Overreact To Exam Version Changes

CCNA Certification: Don't Overreact To Exam Version Changes

Whenever a Cisco exam version changes, there's always a lot of chatter about it on the web. The CCNA exams are no exception.

One comment I see often goes like this: " I hear Cisco is going to change Intro / ICND / CCNA exam versions soon, so I'm not going to start studying yet. I'll wait until the new exam comes out." Do not let this happen to you. While some large publishers would have you think these exams change tremendously from one version to another ("updated for the latest exams!"), the simple fact is that the Intro, ICND, and CCNA Composite exams simply don't change much from version to version.Sure, the questions change.

The only people who should be nervous about that are those who are trying to braindump their way to a technical certification.The topics covered on the CCNA exams don't change much at all.

You know you're going to have to demonstrate knowledge of LAN switching, ISDN, Frame Relay, routing protocol behavior, RIP, IGRP, EIGRP, and OSPF. Perhaps some of the more advanced topics will change, but these will be minor changes at best. Cisco announces these changes on their website well in advance (and you'll read about them here, too), so you won't be left with no time to study.

Whatever you do, don't fall into the "version change". Don't spend $100 - $150 to hurry up and take an exam before you're ready because of an upcoming version change.When you're ready, you're ready. Time spent learning is never wasted. Get started NOW.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage. The Bryant Advantage's website offers FREE ebooks and tutorials for the CCNA and CCNP exams, FREE subscriptions to "Cisco Certification Central", and sells the best CCNA and CCNP prep courses and books on the market today. Visit his site at www.thebryantadvantage.com today!

chris@thebryantadvantage.comCisco Certification: Becoming A Truly Valuable CCNAChris Bryant

I've been active in the Cisco Certification track for four years, working my way from the CCNA to the coveted Cisco Certified Internetwork Expert title, and during that time I've conducted job interviews and casual conversations with hundreds of CCNAs and CCNA candidates.

The CCNA is an exciting beginning to your Cisco career, but just having the certification simply isn't enough. A recruiter or interviewer isn't going to be impressed just with the cert; you've got to have some real-world knowledge to back it up.

I've been down that road myself, and sat on both sides of the CCNA job interview table. With that in mind, I'd like to offer to you some tips on becoming a truly valuable and employable CCNA.

Get some hands-on experience. I know the trap well; you can't get experience until you get a CCNA, and you can't get a CCNA without real experience. Well, actually, you can, but do you want to?

Working on simulators is fine to a certain extent, but don't make the classic mistake of depending on them. I've seen plenty of CCNAs who were put in front of a set of routers and really didn't know what to do or how to put together a simple configuration, and had NO idea how to begin troubleshooting. Simulators fail to help you develop the analytical and logical skills that you must have to be an effective troubleshooter.

There are CCNA classes that offer you the chance to work with industry experts on real Cisco equipment. Beyond that, you can put together your own CCNA rack for less than $500 by buying used routers. Some people think that's a lot of money, but this is the foundation of your career. Treat it that way. The work you do now is the most important work you'll ever do. Do it on real Cisco equipment. The skills I learned as a CCNA helped me all the way up to the CCIE.

Besides, after you get your CCNA (and after that, hopefully you'll choose to pursue the CCNP), you can always get some of your money back by selling the equipment. The hands-on experience you gain this way is invaluable.

(Ill also soon be offering remote equipment access for CCNAs and CCNPs. Watch for it!)

Know binary math. Do NOT go the easy route of memorizing a subnet mask chart for the CCNA exam. I know some people brag about being able to pass the CCNA exam without really understanding binary math. I've seen those people on the other side of the interview table, and they're not laughing when I ask them to do a subnetting question. They're not laughing when they can't explain or create a VLSM scheme. That chart does nothing to help you understand what's going on.

If you can add and know the difference between a one and a zero, you can do binary math. Don't let the name intimidate you. Become a REAL CCNA -- learn binary math !

Run "show" and "debug" commands. No commands help you truly understand how things work in a Cisco network than show and debug commands. As you progress through the Cisco certification ranks, you'll be glad you started using these at the CCNA level.

Do you need to know these commands for the exam? Probably not. Do you need them to be successul in the real world? Absolutely.

The Cisco certification track has been great to me, and it can boost your career as well, whether you stop at the CCNA, CCNP, or go all the way to the CCIE. It's the skills you develop today that will truly make you a networking engineer. Don't take shortcuts or get the attitude of "just passing the exam".

It's what you achieve after the exam that counts, and it's the work you put in before passing the exam that makes those achievements possible.

Good luck !

Chris Bryant, CCIE #12933

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage. The Bryant Advantage's website offers FREE ebooks and tutorials for the CCNA and CCNP exams, FREE subscriptions to "Cisco Certification Central", and sells the best CCNA and CCNP prep courses and books on the market today. Visit his site at www.thebryantadvantage.com today!

chris@thebryantadvantage.comCisco Certification: Debug and Show commands for ISDNChris Bryant

The major reason I recommend getting your hands on real Cisco equipment rather than a simulator is that real Cisco routers give you the chance to practice and learn show and debug commands.

The knowledge you acquire from debugs is invaluable. Frankly, its this knowledge that puts you above the average CCNA who doesnt have that hands-on experience. Watching debugs in action also gives you a head start on the CCNP. Since 90 95% of CCNAs go on to pursue the CCNP, its a great idea to get started with debugs now.

Dont make the mistake of waiting until youre studying for your CCNP and CCIE to start learning debugs and shows. The work you do for the CCNA is the foundation for everything youll do in the future.

Never, ever, ever practice debugs on a production network. There are debugs that will give you so much information that the router actually becomes overloaded and then locks up. Never practice debugs on a production network.

Its important to know the proper show and debug commands for ISDN for several reasons. First, by watching ISDN in operation, you can see its processes and better understand whats going on. Secondly, its difficult if not impossible to properly troubleshoot ISDN without knowing the proper show and debug commands. (Its easy to overlook an ISDN authentication error just by looking at the configuration, but running debug ppp negotiation will quickly show you where the problem lies.)

Lets take a look at the ISDN show and debug commands that every CCNA and CCNP should know.

Show ISDN Status

If you only know one ISDN show command, its got to be this one. Always use this command after configuring your ISDN switch type and any necessary SPIDs. The command will show you the switch type (and will also show you if you did not configure a switch type), and whether the SPIDs you entered are valid:

R1#show isdn statusGlobal ISDN Switchtype = basic-ni    ISDN BRI0 interface        dsl 0, interface ISDN Switchtype = basic-ni    Layer 1 Status:        ACTIVE    Layer 2 Status:        TEI = 91, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED        TEI = 92, Ces = 2, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED    Spid Status:        TEI 91, ces = 1, state = 5(init)            spid1 configured, no LDN, spid1 sent, spid1 valid               Endpoint ID Info: epsf = 0, usid = 1, tid = 1        TEI 92, ces = 2, state = 5(init)            spid2 configured, no LDN, spid2 sent, spid2 valid               Endpoint ID Info: epsf = 0, usid = 3, tid = 1    Layer 3 Status:        0 Active Layer 3 Call(s)    Activated dsl 0 CCBs = 0    The Free Channel Mask:  0x80000003

Once in a while, youll get this output from show isdn status:

R2#show isdn statusThe current ISDN Switchtype = basic-ni1ISDN BRI0 interface    Layer 1 Status:        ACTIVE    Layer 2 Status:        Layer 2 NOT Activated    Spid Status:        TEI Not Assigned, ces = 1, state = 3(await establishment)            spid1 configured, no LDN, spid1 NOT sent, spid1 NOT valid        TEI Not Assigned, ces = 2, state = 1(terminal down)            spid2 configured, no LDN, spid2 NOT sent, spid2 NOT valid

Check your running configuration, and if the SPIDs look good, simply close the BRI interface and open it again. Then run show ISDN status again. If you then see spids are valid, youre ready to proceed. If you still see a message that the spids are invalid, youve most likely mistyped the SPID.

Show Access-List

Whats this command got to do with ISDN? Everything.

Remember how the ISDN link comes up in the first place? Interesting traffic. By default, there is no interesting traffic. You define interesting traffic with the dialer-list and dialer-group commands, AND the access-list command. If you have a problem with your link never coming up or with it coming up and staying up, use this command to see what traffic has been defined as interesting.

Show Dialer

Another helpful command to determine why an ISDN link is coming up and staying up. This command shows you how many successful calls and failed calls have taken place, what the current idle-timer value is (by default, its 120 seconds), and most importantly, what the source and destination was for the current interesting traffic:

R1#show dialerBRI0 - dialer type = ISDNDial String      Successes   Failures    Last called   Last status8358662                  1                 0           00:00:59       successful0 incoming call(s) have been screened.0 incoming call(s) rejected for callback.BRI0:1 - dialer type = ISDNIdle timer (120 secs), Fast idle timer (20 secs)Wait for carrier (30 secs), Re-enable (15 secs)Dialer state is data link layer upDial reason: ip (s=172.12.21.1, d=172.12.21.2)   Time until disconnect 62 secs   Connected to 8358662 (R2)

Here, you can see that the idle-timer value is at its default, that there are 62 seconds left until the link comes down (unless interesting traffic resets the timer), and that the source of the interesting traffic was 172.12.21.1 and the destination is 172.12.21.2. If that destination is the multicast address of a routing protocol say, 224.0.0.5 for OSPF you know what traffic is keeping the line up.

Show ISDN History

Want to see what calls have been made in the last 15 minutes? Just run this command. Its helpful if youre walking in to an ISDN troubleshooting situation and want to see what calls have been made.

R1#show isdn history-------------------------------------------------------------------------------- ISDN CALL HISTORY--------------------------------------------------------------------------------History table has a maximum of 100 entries.History table data is retained for a maximum of 15 Minutes.--------------------------------------------------------------------------------Call Calling Called Remote Seconds Seconds Seconds ChargesType Number .Number Name Used Left Idle Units/Currency-----------------------------------------------------------------------------------------------------------Out 8358662 R2 121 0Out 8358662 R2 121 0-----------------------------------------------------------------------------------------------------

Debug PPP Negotiation

Not only do you need to know this command for your CCNA and CCNP exams, you MUST know it to be an effective ISDN troubleshooter.

When PPP authentication is first configured, its simple to mistype a password, or forget to configure a username / password combination. Instead of continually reading your running configuration to see what the problem is, run debug ppp negotiation and send a ping to bring the line up. Youll quickly see where the problem is.

R2#debug ppp negotiationPPP protocol negotiation debugging is onR2#ping 172.12.21.1BR0:1 PPP: Phase is AUTHENTICATING, by bothBR0:1 CHAP: O CHALLENGE id 1 len 23 from "R2"BR0:1 CHAP: I CHALLENGE id 1 len 23 from "R1"BR0:1 CHAP: O RESPONSE id 1 len 23 from "R2"BR0:1 CHAP: I SUCCESS id 1 len 4BR0:1 CHAP: I RESPONSE id 1 len 23 from "R1"BR0:1 CHAP: O SUCCESS id 1 len 4

By mastering these simple ISDN show and debug commands, you increase your chances of passing the CCNA and CCNP exams greatly, and vastly improve your on-the-job skills.

I recommend you visit www.cisco.com/univercd for more show and debug commands. Learning to negotiate this valuable online resource will truly help you become more valuable on the job. Every Cisco router and switch command, along with default and usage guidelines, can be found on this site. Ill have an article posted soon to help you learn your way around the site; in the meantime, I urge you to begin adding this website to your troubleshooting toolkit.

Chris Bryant
CCIE #12933

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage. The Bryant Advantage's website offers FREE ebooks and tutorials for the CCNA and CCNP exams, FREE subscriptions to "Cisco Certification Central", and sells the best CCNA and CCNP prep courses and books on the market today. Visit his site at www.thebryantadvantage.com today!

chris@thebryantadvantage.comCisco Certification: Configuring CHAP on ISDNChris Bryant, CCIE #12933