Firstly, the goals of what you need to know. The following is a list of the things you need to know really well - in other words, you should be able to recall these things instantly.
- Subnetting. You need to be able to calculate subnet numbers ( subnet address, broadcast address, first and last useable IP addresses ) in your head, and fairly quickly for any IP class and number of subnet bits.
- Routing protocols. These include RIP, RIP2, IGRP, EIGRP and OSPF. You'll need to know the types for each ( distance vector, link state, hybrid ), the metrics ( bandwidth, speed ) and administrative distances for each one. A fair idea of the types of tables that each uses will be useful.
- WAN protocols. Know all the encapsulation types ( PPP, DLCI, Frame Relay, etc ) and the quirks of each one. In particular, remember the default encapsulation for router interfaces.
The Approach
As in my first exam, I bought the Cisco book. This time I got Todd Lammle's CCNA book ( published by Sybex ) which I must say was excellent. It was short ( compared to the behemoths that Cisco sells ) and to the point. It didn't include pages of unnecessary detail, some bits were amusing and it was particularly easy to read. The review questions and practical excercises were great. But note this: the exam was a little harder than the questions in the book and trial exams on the CD.The Practice
Get some practice on routers ( and maybe switches too ). You need to practice setting up and fault-finding on routers and switches. You should practice until you can fully configure a pair of routers from scratch to talk to each other over serial interfaces within a minute or two.Switches are much simpler than routers, and you may be able to get away with not having one to practice on depending on how confident and experienced you are.
Unfortunately, the excellent practice site R1R2.com seems to be no longer available, which leaves you a few choices ( in my order of preference ):
- Beg, steal, borrow, or buy some hardware. OK, maybe not steal, but the other options are worth considering. At a bare minimum, you'll be wanting a couple of 1600 series routers with a serial WIC in each and a serial crossover cable. You can often get these on Ebay for quite cheap ( and you can usually sell them again when you've finished ). Make sure they're running a fairly recent version of IOS such as 12.3 or higher. The good thing about this is that you can actually touch and see the cables, power-off the routers, and do stuff like messing with the configuration register and recovering the enable password. Great fun.
- Various companies sell simulators which are very good. Routersim and Boson are examples. I haven't used these, but many people recommend them.
- I've heard that there are some sites on the Internet that run paid-for router labs where you can access real equipment ( or maybe very good simulators ) over the Internet.
- The Cisco web site has a Learning Centre which is worth exploring for trial tests and (very basic) simulators.
The Exam
While various agreements prevent me from giving away details, here's some tips which may help you in the actual exam:- Get comfortable before you start. You've usually got a bit of time to do a "test introduction" - it's a good idea to do this just to calm your nerves and get used to the types of questions that you'll be facing.
- Watch your time. You could be very busy: I found the exam took more work than the trial exams in Todd Lammle's Sybex book.
- Use pencil and paper only when you need to. Because there isn't much time to work things out by hand.
- You can usually eliminate one or two of the multi-choice answers straight away. Get used to this process by doing lots of trial exams and eliminate answers quickly and consistently in your head ( not on paper, remember? ).
- If you see questions that you haven't studied for, then eliminate the bogus answers, take your best guess and move on. Don't sweat it out. Some questions are "trial" questions which may be outside the current CCNA syllabus and you won't be marked on these.
- Be prepared for "complex" questions. For example, single questions that demand knowledge of subnetting and routing protocols or questions that may show a moderately complex network and ask you to find the fault in it.
Quick Links
A few quick links to get you started.Well, that's about it. The good thing about the CCNA exam is not that it teaches you a lot about Cisco specific products, but that you will learn a lot about TCP/IP networking. And these days, such knowledge is really essential to get a good job in IT. I've met many people in IT that don't understand basic things like subnetting, VLANs and WAN protocols and they often get into trouble when tackling simple problems and designing what should be simple solutions.
Good Luck
But when you know your stuff, luck isn't necessary.
Kerry Thompson, CCNA CISSP
Saturday, October 1, 2005