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Network Warrior
Fatty writes "Entry level certifications such as the Cisco Certified Network Associate (CCNA) have become the source of many jokes to people in the industry, largely because of the seemingly inept people that proudly display their certifications. This is made worse by the volume of books geared only to get people through the exam. Network Warrior bills itself as the exact opposite — if the subtitle is to be believed it contains "Everything You Need to Know That Wasn't on the CCNA Exam". With everything from the architecture of the 6500 to layers 8 and 9 of the OSI model (politics and money), it does a pretty good job." Read below for the rest of Sean's views on this book.
Network Warrior: Everything You Need to Know That Wasn't on the CCNA Exam
author
Gary A. Donahue
pages
598
publisher
O'Reilly
rating
9
reviewer
Sean Walberg
ISBN
9780596101510
summary
A practical look at what you really need to know to run a Cisco network
The CCNA exam is supposed to test a candidate's understanding of networking fundamentals. Over the years it has expanded to include more advanced material, and now covers networking theory, switching (including spanning tree and VLANs), and some of the intermediate routing protocols such as EIGRP and OSPF. Despite the breadth of content the exam doesn't (and can't) cover things that many network folk take for granted, even things like what the "demarc" is (short for demarcation point, the the place where the carrier's responsibility ends and yours begins). While the exam's topic list is broad, the level of detail is shallow in most places. Someone may study spanning tree enough for the exam, but have no clue where to place their root bridge when they get into the real world.
It is for this reason that I found Network Warrior to be helpful. It's goal is to point out both the technical areas in which the CCNA falls short, and to teach the reader the non-Cisco aspects of running a network.
Technically I found this book quite sound. There were a few things one might disagree with but nothing that detracted from the rest of the book. In several spots the author was keen to point out behaviors that deviated from the documents, such as in Quality of Service (QoS) and in upgrading certain modules in the 6500 chassis. He also illustrated where the theoretical concepts on network design fall short in the real world.
Routing and switching takes up the first third of the book. The switching section is largely a review of the CCNA material with some notable exceptions. First and foremost is a chapter exclusively on autonegotiation. The CCNA exam may only discuss how to set a port to a fixed speed, but anyone who has worked with a network for more than a few weeks will have run into a speed or duplex mismatch. This chapter explains some of the history behind Ethernet and its relevance to autonegotiation, explains how it works, how it fails, and how to recognize the problem, and finally offers advice on when and where to use autonegotiation.
The second major deviation from the CCNA switching syllabus is in depth coverage of Etherchannel and spanning tree (STP) Both of these protocols are integral parts of network design and operation, but the exam barely touches Etherchannel and doesn't get into the complexities of spanning tree (though this changes with each iteration of the exam.) Network Warrior provides techniques and a demonstration of finding a layer 2 loop. Surprisingly though, there is only mention of standard 802.1d legacy spanning tree and some Cisco extensions such as Per VLAN STP and backbone fast, and no mention of the newer standardized enhancements of 802.1s/w (rapid spanning tree and multiple spanning tree) which have been in common use and have been put on the latest version of the exam (released after this book went to press)
The third deviation is the inclusion of CatOS commands instead of just IOS like the exam. As the author repeatedly points out, CatOS is in use on many 6500 chassis and is still in active development, so there is no reason not to know it. This theme continues throughout the book whenever the 6500 is used as an example, which is often.
The routing chapters are full of new material. The sections on the routing protocols themselves are short and don't add much beyond what the CCNA certification teaches. Redistribution and route-maps, however, are well explained. These two technologies which can be used separately or together can be found on almost any network and are very complex. I thought these sections were well done, as they gave enough details to be practical without getting down into all the different scenarios. Tunnels make an appearance in these chapters, which themselves aren't very complex, but aren't a part of the CCNA blueprint.
At this point, roughly page 180 of 550, the rest of the material isn't found in the CCNA blueprint.
Part 3 of the book is all about multilayer switching, specifically the 3750 and 6500 platforms. In particular the description of the 6500 architecture is much more succinct that can be found by searching on Cisco.com. There is an in depth explanation of how the various backplanes on the chassis works, which leads to an explanation of how to determine which cards are slowing down your switch.
I think the hidden gem of the book is part 4, though, which is all about telecom. In these chapters are an explanation of how carriers operate and how to speak the lingo of telecom techs. Even though networks are moving to Ethernet based services, traditional DS1, DS3, ATM, and frame-relay networks are still commonplace. The book has a solid explanation of how TDM based circuits actually work, the various options available to you, and how to properly order and troubleshoot them. I think back to when I was getting started in this field, and dealing with carriers was difficult.
Quality of Service, the features that let you guarantee and limit bandwidth to different types of traffic, have a section in this book too. The book largely focuses on the simple weighted-fair queuing (WFQ) and the current class-based WFQ with low latency queuing for voice. Configuration instructions can be found on Cisco's site easily enough, but Network Warrior delves into some of the behavioral aspects the documents shy away from such as when the queuing mechanisms actually get used. There is also a solid look at how to make sure the QoS is working as intended.
In the middle of all of this are chapters on the firewall and load balancing modules for the 6500, the PIX firewall, and IOS based load balancing. For someone with an ecommerce slant these might prove helpful, but given that these topics are books in themselves, it's hard to do them justice in a few chapters.
The last part of the book is on network design, which encompasses not only the steps needed to build a network, but also planning IP address allocations and how to pitch your ideas to management. Again, the book is not trying to be the definitive text on the subject, but it manages to impart a few words of wisdom, especially the so-called "GAD's Maxims", and "How not to be a computer jerk".
Well thought out examples were plentiful, along with anecdotes from the author, usually showing the consequences of doing things wrong. The illustrations did a great job of conveying the point at hand. Even though I've been doing this stuff for a while I learned several time saving techniques that I've already been able to put to use.
This is a great book for people just getting into the industry, with their CCNA or without. It offers practical advice rather than dry textbook like explanations which is a welcome change. Even those with a few years of experience under their belt will be happy reading through Network Warrior.
Sean Walberg is a network engineer and author living in Winnipeg, Canada.
You can purchase Network Warrior from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
The CCNA exam is supposed to test a candidate's understanding of networking fundamentals. Over the years it has expanded to include more advanced material, and now covers networking theory, switching (including spanning tree and VLANs), and some of the intermediate routing protocols such as EIGRP and OSPF. Despite the breadth of content the exam doesn't (and can't) cover things that many network folk take for granted, even things like what the "demarc" is (short for demarcation point, the the place where the carrier's responsibility ends and yours begins). While the exam's topic list is broad, the level of detail is shallow in most places. Someone may study spanning tree enough for the exam, but have no clue where to place their root bridge when they get into the real world.
It is for this reason that I found Network Warrior to be helpful. It's goal is to point out both the technical areas in which the CCNA falls short, and to teach the reader the non-Cisco aspects of running a network.
Technically I found this book quite sound. There were a few things one might disagree with but nothing that detracted from the rest of the book. In several spots the author was keen to point out behaviors that deviated from the documents, such as in Quality of Service (QoS) and in upgrading certain modules in the 6500 chassis. He also illustrated where the theoretical concepts on network design fall short in the real world.
Routing and switching takes up the first third of the book. The switching section is largely a review of the CCNA material with some notable exceptions. First and foremost is a chapter exclusively on autonegotiation. The CCNA exam may only discuss how to set a port to a fixed speed, but anyone who has worked with a network for more than a few weeks will have run into a speed or duplex mismatch. This chapter explains some of the history behind Ethernet and its relevance to autonegotiation, explains how it works, how it fails, and how to recognize the problem, and finally offers advice on when and where to use autonegotiation.
The second major deviation from the CCNA switching syllabus is in depth coverage of Etherchannel and spanning tree (STP) Both of these protocols are integral parts of network design and operation, but the exam barely touches Etherchannel and doesn't get into the complexities of spanning tree (though this changes with each iteration of the exam.) Network Warrior provides techniques and a demonstration of finding a layer 2 loop. Surprisingly though, there is only mention of standard 802.1d legacy spanning tree and some Cisco extensions such as Per VLAN STP and backbone fast, and no mention of the newer standardized enhancements of 802.1s/w (rapid spanning tree and multiple spanning tree) which have been in common use and have been put on the latest version of the exam (released after this book went to press)
The third deviation is the inclusion of CatOS commands instead of just IOS like the exam. As the author repeatedly points out, CatOS is in use on many 6500 chassis and is still in active development, so there is no reason not to know it. This theme continues throughout the book whenever the 6500 is used as an example, which is often.
The routing chapters are full of new material. The sections on the routing protocols themselves are short and don't add much beyond what the CCNA certification teaches. Redistribution and route-maps, however, are well explained. These two technologies which can be used separately or together can be found on almost any network and are very complex. I thought these sections were well done, as they gave enough details to be practical without getting down into all the different scenarios. Tunnels make an appearance in these chapters, which themselves aren't very complex, but aren't a part of the CCNA blueprint.
At this point, roughly page 180 of 550, the rest of the material isn't found in the CCNA blueprint.
Part 3 of the book is all about multilayer switching, specifically the 3750 and 6500 platforms. In particular the description of the 6500 architecture is much more succinct that can be found by searching on Cisco.com. There is an in depth explanation of how the various backplanes on the chassis works, which leads to an explanation of how to determine which cards are slowing down your switch.
I think the hidden gem of the book is part 4, though, which is all about telecom. In these chapters are an explanation of how carriers operate and how to speak the lingo of telecom techs. Even though networks are moving to Ethernet based services, traditional DS1, DS3, ATM, and frame-relay networks are still commonplace. The book has a solid explanation of how TDM based circuits actually work, the various options available to you, and how to properly order and troubleshoot them. I think back to when I was getting started in this field, and dealing with carriers was difficult.
Quality of Service, the features that let you guarantee and limit bandwidth to different types of traffic, have a section in this book too. The book largely focuses on the simple weighted-fair queuing (WFQ) and the current class-based WFQ with low latency queuing for voice. Configuration instructions can be found on Cisco's site easily enough, but Network Warrior delves into some of the behavioral aspects the documents shy away from such as when the queuing mechanisms actually get used. There is also a solid look at how to make sure the QoS is working as intended.
In the middle of all of this are chapters on the firewall and load balancing modules for the 6500, the PIX firewall, and IOS based load balancing. For someone with an ecommerce slant these might prove helpful, but given that these topics are books in themselves, it's hard to do them justice in a few chapters.
The last part of the book is on network design, which encompasses not only the steps needed to build a network, but also planning IP address allocations and how to pitch your ideas to management. Again, the book is not trying to be the definitive text on the subject, but it manages to impart a few words of wisdom, especially the so-called "GAD's Maxims", and "How not to be a computer jerk".
Well thought out examples were plentiful, along with anecdotes from the author, usually showing the consequences of doing things wrong. The illustrations did a great job of conveying the point at hand. Even though I've been doing this stuff for a while I learned several time saving techniques that I've already been able to put to use.
This is a great book for people just getting into the industry, with their CCNA or without. It offers practical advice rather than dry textbook like explanations which is a welcome change. Even those with a few years of experience under their belt will be happy reading through Network Warrior.
Sean Walberg is a network engineer and author living in Winnipeg, Canada.
You can purchase Network Warrior from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
Can't geeks do anything network related without pretending to be gladiators? Wardriving, network warrior, DMZ, ...
BTW--what is this 6500? And what is this .... 'OSI model'? Is that a new router or something?
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After moving to a different state, the first interview I went on was with a larger company. After being a Windows/Mac admin (this is in the mid-90s) for a couple years, I was vaguely surprised that I knew the answer to almost none of their very obscure questions. I had been one of three administrators of a medium-sized WAN at my old job, and nothing they asked seemed relevant at all to real-world circumstances. Disappointed at my lack of knowledge (not to mention the fact I didn't get the job), I decided to study for the MCSE, as there was clearly stuff I didn't know.
To my surprise, every single one of their obscure, imaginary-world answers were straight from sample MCSE tests. And after 10 more years working in a mixed environment, those questions still don't apply.
I find the discussion of this to not be accurate. The CCNA is intended to be an entry level certification for someone with little experience in networking. It is this fact that should not be overlooked when said person has a CCNA and does not know everything there is to know about configuring a router/switch. Also, topics such as multilayer switches and QoS are NOT entry level subjects. These topics are covered in great detail for the CCNP certification, which requires 4 exams to get (on top of a CCNA). Certifications show a certain level of understanding, and for the CCNA, the level of understanding should not be read as anything more than entry-level.
The same goes for anything else. Would you expect someone with a B.S. in computer science to understand advanced research topics in computing that masters and/or phd students work on?
Good one, I wish I could have added that to various exam answers over the years. :-)
Please Do Not Throw Sausage Pizza Away P? M?
Layers 8 and 9 can't be politics and money. As layer 7 is described as the layer closest to the user, I've long asserted that layer 8 _is_ the user. With users learning what id10ts and pebkacs are, "layer 8 error" makes for a subtle and safe alternative ;)
That's exactly the kind of shop you don't want to work for. If they don't understand which questions to ask then they don't understand what it is they need you to do (or say, that you're doing it right). Terrible situation to be stuck trying to work in.
Quack, quack.
I firmly believe that a certification proves nothing. I have had disdain for them ever since the company I was working for hired a SCSA (Sun Certified Systems Administrator) who didn't have a clue about anything that wasn't in SMC (or in SMC for that matter). But the big boss said, "He must know what he's doing, he's certified." So, I got my first certification out of spite (SCSA).
Since then I have gotten several certifications, not because they mean anything to me (other than I can study for and take a test), but because HR type personnel will rule you out as a potential candidate based solely on your certification status.
CCNA's and MCSE's are good certifications, it essentially tells me that people know at least how to reboot routers, pull cable, reboot microsoft machines, and apply basic patches. I use these qualifications to find entry level helpdesk people, and provide better training if they cut the mustard after a few months.
Sorry, not on topic, but...
I get tired of hearing this crap about certification X being a joke. Any kind of memorized knowledge is a joke if you can't apply it to real world situations. There are too many people out there getting certifications without the requisite knowledge and experience necessary to actually get something done.
If a company can't interview a candidate properly and gets stuck with someone who has no ability to think for themselves, then it is there own damn fault. Too many companies just want the hiring process to be as easy as reading a list of certifications an applicant has.
but degree != critical thinking so what is your point? I am tired of my HR team sending candidates with a degree but no real experience because "they have an Engineering degree".
They also get you a job on Geek Squad.
Being a pervert is optional.
Please Do Not Throw Sausage Pizza Away, Per Management
This is a really nicely put together book. It fills a nice niche at Intro to Middle level of the Cisco areas somewhere just after the CCNA and probably touching on some of the CCDA topics. Its not meant as a real cookbook - that's why there is the excellent Cisco IOS cookbook also from O'Reilly which deals with the particular obsure, nutty but damn valuable gems that are out there, from Net engineers who've had the long hours and coffee to hand us great tricks.
How to place this book is like this, so you've finished or are close to your CCNA and would like some sound practical advice to round out the course or maybe to help you revise it, well this is the book for you. If you know more and are in deeper Cisco terrority well you might like this but you'd probably prefer the Cisco IOS cookbook.
Off topic - I also got a copy of Limoncelli et al's revised version of The Practise of System and Network Administration in the same batch, given the first edition was most excellent there is little to say except the second is even better. Common sense and practical knowledge without getting lost in OS or application issues.
Grammar flames are for those who have nothing actually useful to say, but certainly try too hard to make it seem the opposite. Not only is this all about TYPED WORDS (spell/grammar check doesn't always do you well), but I'd gather most slashdotters best language isn't English. Mine is C++.
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
Clearly a certification is less evidence of competency than 5 years of experience (assuming you can actually verify that the experience is relevant), but often when choosing between candidates with limited experience the only difference you can determine is that one passed a test and the other never took one. All things being equal, I'd choose the one who has objectively demonstrated some level of knowledge.
Cisco Certifications are no different than Microsoft or any other vendor-specific certifications. And quite frankly, you're an ass for suggesting anyone with a Cisco cert is a moron. Vendor-specific certifications can offer value to both employers and employees by recognizing a certain level of knowledge about a particular product or technology. There are certain nuances to the Cisco IOS that might demonstrate that even though a candidate may not know everything there is to know about OSPF or EIGRP, that they are at least comfortable with the IOS, and can figure out how to do something without having their hand held. The certification industry helps drives product sales. If I have a number of Cisco certified staff working for me, am I really going to invest in 3Com or Juniper when I know there may be (an albeit slight) learning curve for them? I hold many certifications, myself. Most of them are vendor specific (primarily Microsoft, because I worked as a Microsoft Certified Trainer; and I certified in everything I taught); but not all of them. I don't think it's fair to dismiss the CCNA; but I think the Network+ certification might be more valuable to an employer who is looking for general network skills without vendor-specific implementation. But, there's always going to be the elitist asses who dismiss all certification programs outright. I guess when you fail the test two or three times, you might become embittered.
And I think you're dead-on. It's taken me years to learn that. That and the fact that not only am I replaceable, but so is my employer. It's definitely a two-way street and change isn't alway bad (it's usually opportunity actually, whatever you might chose to make of it).
Quack, quack.
I went into networking with NO prior experience other than setting up a simple linksys router for home-use. I learned everything I know about networking ON the job. It took me a good 3 months just to get the lingo and basics down, but afterwards I had to start plowing through vlans and the different routing protocols like BGP and OSPF.
My point is had I actually studied for a CCNA before I was hired, I would've hit the ground running most likely would've advanced to my NOC position in 3 - 4 months less time. The CCNA is not a joke. It may not teach you ALL the terminology and EVERYTHING you need to know about EVERYTHING, but it's a hell of a good start.
You're nothing; like me.
turn up the jukebox and tell me a lie
Having just obtained both CCNA and A+ certifications within the last 9 months, even though neither was really necessary for my current job, I feel the need to defend the CCNA exam by contrasting it with the A+ exam.
The A+ exam is a complete joke. It might have been relevant 10 years ago, but isn't anymore. The vast majority of questions were completely irrelevant today, and mostly irrelevant for any computer faster than 500MHz. Most of it was pure memorization, the kind all those cram books are for. There were very few real-world questions -- less than a half-dozen. There were even a few questions that were nonsense -- none of the answers were applicable, much less valid, and in some cases the question didn't even make sense.
The CCNA, however, is a killer. I took mine in May 2007. The first part of the exam is roughly one-third memorization questions, one-third diagram interpretation questions, and one-third real-world questions. Most of the diagram questions are trick questions with multiple realistic-looking answers. (In other words, you can't just look for the "obvious" answer.) This part of the exam is meant to test your grasp of networking concepts.
The second part of the CCNA exam is what really gets you, though. It's all about configuration. Most of it is spent in a simulator. And not just a simulator for one router or switch, but a simulator for an entire network. One of my questions involved configuring 4 different routers and 3 switches. Oh, and they can disable parts of the simulator to make your job harder -- like having to diagnose a connectivity problem without being able to ping or traceroute. And yeah, they like to throw multiple IOS versions at you to make sure you know the different variations of the commands (especially for switches). You cannot cram for these simulator-type problems.
I tend to consider myself a pretty smart guy. I've been working as a network admin for 10+ years, albeit not with Cisco equipment. I aced the classwork for the CCNA courses without putting forth any effort whatsoever. I did homework in class and never had to come in after hours to catch up. And yet, I had ~45 seconds left on the timer when I finished part 2 of the CCNA exam. It's that tough, and they've got it timed down to the last minute. You do not have time to flounder and guess.
If you don't know your stuff backwards and forwards, you are not going to pass the second half of the CCNA exam. It's that simple.
Now, having said all of that, remember: the CCNA is the entry-level exam. It's not meant to certify that you can walk into a company and rewire an international infrastructure by hand. It's meant to certify that if you put me in front of a router or a switch or a small network that is having problems, I can most likely figure out what the problem is. The building-huge-networks stuff is part of the CCNP, not the CCNA. (The first CCNP class is, after all, "Building Scalable Networks".)
I see plenty of haterade about the CCNA exam, but I never seem to see it from people that have taken the tests. And I have to wonder: for all of those exam-crammers with CCNAs that everyone seems to know, when did they get their certs and are they current? I doubt it.
It's "relevant" in that TCP/IP is based on the ideas of the OSI model, and has a similar, layered architecture. In practice though, TCP/IP doesn't follow the OSI model very closely.
For example, in TCP/IP, there's only one layer above the transport layer, which makes OSI layers 5, 6, and 7 all the same. I suppose you could argue that layer 6 never really existed anyway, but that's neither here nor there.
Similarly while there's a technical distinction between layers 1 and 2, in common practice they are too interrelated to speak of as separable layers.
Does it matter!!! Well I can't tell it anymore, having finished CCNA and SCJP 5, hoped to get a job more easily. But not. Before getting certified I'd hear "How do I know you now anything if you're not certified", after certifications "those are just crap, just piece of paper", well that was a surprise, wasn't it??? Now I'm asking my self is it worth to spend more time and money on the certifications, or continue giving the money to Sun, Cisco, Microsoft, blla blla????
a week doesn't go by that I don't categorize a problem by OSI layer. It's still relevant as a logical abstraction, and it's used as such, regardless of actual protocol implementation.
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Sorry but no you don't. You learn Cisco's way of doing everything which is painfully different from everyone else from Nortel, 3com, HP, Brocade, Adtran, and a number of other vendors.
For every solution there is a standards compliant way to do it and there is a Cisco way to do it. To Cisco's credit their products support the standards but one need only look at the removal of CDP from HP ProCurve products to see why the Cisco way isn't always the best way. Subnetting into VLANs and trunking is basically the same from vendor to vendor. The Cisco exams are more concerned about how you setup LACP on a Catalyst 6500 running IOS 12 vs an older Catalyst running IOS 10 with the biggest difference being syntactical. The old way for instance you had to wipe an ACL completely and add it all back when you wanted to make a change. The new way you just remove the ACL entry you don't want. A much saner way. That's just one example. Cisco isn't even consistent among their product lines. Command sets are different with new releases of IOS, sometimes making it more friendly but I would think consistency would be a better approach.
Is it any wonder my Proxim APs have a very similar command set to my ProCurve switches?
So I would say that knowing the commands to setup LACP doesn't necessarily teach you the concept behind why you would want to do that and get into how it affects your STP setup.
I will say that the CCNA is still one of the better certs out there. Certainly light years better than any of the Microsoft or Oracle certs.
Perhaps so, but how do you hire a tech person to weed out the "puke learners" if you don't have one already?
I see this biting people often. I'm a networking contractor in my spare time so I often get called in by word of mouth to repair something for a company who has no IT guy because the IT guy was a moron and broke stuff and left them with no documentation.
I have seen one manager's test for whether or not the tech guy was nerdy enough for the job though. He asked who the proponent thought would win in a fight - Battlestar Galactica, or The Enterprise, and why.
Funnily enough, it worked pretty well.
Trick I use to remember...
All People Seem To Need Data Processing =
A)pplication 7
P)resentation 6
S)ession 5
T)ransport 4
N)etwork 3
D)ata-Link 2
P)hysical 1
Now do I get a gold star?
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