70-293 MS training book has serious Errors! Please comment

Discussion in 'MCSE' started by Graham Allen, Sep 15, 2009.

  1. Graham Allen

    Graham Allen Guest

    I feel I have to post this because of how bad the official MS 70-293 training
    book is.
    This is the book in question
    I know MS don't directly write this book but it is licensed under MS press
    and they should vet it at least!

    Firstly let me say that I am already pretty knowledgeable on the 2003 OS. I
    am going through this book to brush up on my skills in prep for the exam.
    In particular these errors are relating to subnetting. I have only got into
    the early part of the book and already I have found loads of mistakes.
    This post may be a bit difficult to read but I have done my best to clear
    things up where I can so my apologies if you find it hard to follow.

    Let me explain the problem. On page 2-32 you have some practice questions.

    The first one gives you a network subnet of with several
    questions. The ones that are important (and answers wrong for that matter)

    The First subnet?
    The last Subnet?â€

    Now, I have always been frustrated with the vagueness of MS Exam questions
    because usually you need a bit more information as you can answer the
    questions with different answers and all will be technically correct. MS
    however wants you to answer them a specific way and usually expect you to
    make assumptions.

    Let’s look at the first question:
    Ok we work out that the subnet mask is This means that each
    subnet increments by 32 (256-224 subnet mask).
    Depending on your experience/training the first subnet can be:
    Network ID:
    Broadcast ID:
    IP Range: –
    Note: This is the answer I came up with!

    Or if you count the first and last subnets as invalid ranges (which we will
    come onto later on) then your first subnet is as follows:
    Network ID:
    Broadcast ID:
    IP Range: –
    Note: This is the “correct†answer in the MS training material.

    So straight away you have 2 different answers! MS make no explanation in the
    chapter about which method should be used. The second method conforms to RFC
    specification but MS version of TCP/IP allows you to start the first subnet
    on Oh well...Let’s just hope we get it right in a lucky guess!
    Anyway we have the training material right?? So we can see which is the
    correct method at least for the MS exam?? Wrong! Based on the answer in the
    book this means we are using the second method which states that the first
    and last subnet ranges are invalid. In the second question which asks what
    the last subnet is, again you have 2 options again:

    Method 1 (where you don’t count the first and last subnets as being invalid)
    Network ID:
    Broadcast ID:
    IP Range: –

    Method 2 (where you count the first and last range is invalid)
    Network ID:
    Broadcast ID:
    IP Range: –
    Now according to the book then the last subnet should be what is in method 2
    but it isn’t. The answer says the results of method 2!! So not only is the
    question vague in the first place but it now is applying one rule on question
    and a completely different rule on the second question!!! So what is the
    correct one? How am I meant to have any faith in the MS exam answers based on
    Now if you thought that was bad then see the following forum post. The
    person doing the explaining is basically saying the same as me but at the
    bottom he has provided a link that takes you to an MS support page stating
    the corrections and amendments for this book. This problem isn’t listed! I am
    paying good money for this training material which is riddled with errors and
    the best MS can do is update them on a site and not even reference this in
    the book!! It was by chance that I found this and investigated further!
    Here is the link to the excellent post I found

    Don’t worry about the link, it is cached copy from the Google servers.
    Mysteriously the original post has been deleted..hmm. I think MS may have
    taken it down. If you are scared of the URL then go to Google and type this
    in “Subnetting in 293 in MCSE Examâ€. The first post that comes up click it
    and it will say the post doesn’t exist. Go back then click the “cached†link
    by the green URL. This will take you to the URL above and a cached copy of
    the original post a Google server.

    Let’s do some more analysis on this...I found a total of 18 questions
    relating to subnetting in this section of the book 2-32. 6 of them are wrong,
    that is a third. That means that if I took the exam with just these questions
    and answered everyone correctly a third of them would be wrong which would be
    an instant fail!! This is unacceptable and I think this is something that
    needs fixing!
    I will list all the questions now and why they are wrong.

    3 questions on 2-32 in the same format as the examples I gave above just
    using different IP subnets. Of course all of these are wrong because one rule
    is applied to the first subnet and a different one to the last subnet.

    The next set of questions are based on a case scenario. It is a massive
    load of text but I will just mention the facts that are relevant to the
    incorrect answers:
    • You have been assigned a private IP subnet of
    • You have 4 LAN’s and this subnet must be further subnetted so that each
    LAN has 1 (and only 1) subnet.
    • The maximum amount of host’s on a LAN is 100.
    Question 5 Page 2-52
    Which IP range classes can you not use when selecting a network address?
    (choose all that apply)
    Class A
    Class B
    Class C
    Class D

    I chose class D only but the book says Class C and D.
    Firstly we know a class D is a multicast so it can’t be used. Now let’s look
    at why I see Class C as being valid.
    Again we have to make assumptions...sigh! Based on the fact that the book
    says C and D are not valid but A and B are I presume they are referring to
    the network address range they gave you earlier and the question
    implies you can choose an IP range of your choice. The reason I say this is
    because if we use then this is a class B network therefore all
    answers would not be valid except the Class B answer. But because they say
    class A is valid then they can’t be saying you must stick with the address address they brought up earlier. So here comes the next
    problem...if you are allowed to use any IP range then all of them would be
    valid except for class D which is the answer I gave?!?!
    I thought about this for a while and tried to come up with a solution that
    would fit with the MS answers and here is what I got.
    The only reason I can see them saying a class C is invalid is if you base it
    on the fact that each subnet must be able to accommodate 100 PC’s (as stated
    in case scenario). Again we have to make another assumption though for this
    to work. This assumes that the question means you must subnet the network
    however. A class C network allows for 254 hosts therefore this would be valid
    so I assume you must subnet it. If you subnet it by just 1 bit you narrow it
    down to 128 hosts. Now this is still valid but using 1 bit only allows us to
    have 2 subnets of the class C network (as I said we must assume that it wants
    us to subnet because a normal class C network would valid). Because we only
    have 2 subnets (and now a third assumption) these 2 subnets are invalid
    because you can’t use the first and last subnets of a network (using method 2
    in above examples). Still with me?? Anyway as you can see there is so much
    ambiguity and assumptions you must make to get this answer correct!!

    Question 6 Page 2-52
    For each answer you selected (in above question) explain why?
    Now because I only selected Class D I would get this wrong because it wants
    me to explain why a class C is wrong.
    Note: The answer the book gives for the Class C not being valid states it
    can’t support 100 PC’s. This further supports my idea that the question
    (previously) wants you to subnet the network because a normal class C network
    not subnetted would suffice.

    Question 7 Page 2-52
    Assuming you will use a network in the class B private address range what is
    the max number of subnet ID bits you can use and still have a sufficient
    number of host ID bits to support the comps on each of your networks?
    (This is talking about the network address) My answer was 9
    bits as 7 bits are left for the host ID leaving you with a max 126 hosts per
    subnet. My answer was the same as the book. The answer is correct but this
    affects the next set of questions which is why I have listed it here (bear
    with me!).

    Question 8 Page 2-52
    Using the network specified earlier (What network previously?? The in the case scenario or the one I have just subnetted in the
    previous question) how many subnet ID bits are you using for your network
    See what I mean about being vague?? I thought this question was talking
    about my network which I have just subnetted in the previous question. It
    turns out it wasn’t.
    This reference was to the that is listed in the case scenario.
    It could mean one or the other. I mean let’s think about normal conversation
    flow. If I am talking to you about a object/person/car (for example John)
    then I start talking about Frank then I say “he said he went home†who do you
    think I’m talking about?? I know I would think that Frank went home but
    applying this analogy to the question in the book it would mean I was talking
    about John again now without first telling you I was. It doesn’t matter
    really what you think, my point is that it is too vague a question to say
    “the previous network specified earlier†when you now have 2 different

    Question 9 Page 2-52
    What subnet mask must you use for the unregistered LAN’s on your network?
    Answer (in book):
    Now what network is this referring to?? The in the case
    scenario (question 8) or the generic class B network it asked you to subnet
    in question 7?in each answer you gave for the two separate questions above
    result in different subnet masks.
    I thought it was talking about question 7 so with this it would mean we have
    16 for the class B network and borrow 9 bits to subnet it (as asked in
    question 7). This leaves us with 7 bits for the host thus your subnet mask
    would be which according to the book is wrong.
    But it was talking about which would be correct to get the subnet mask.

    Question 10 Page 2-52
    List the IP address ranges for the first 4 subnets created from your
    unregistered network address?
    I got this wrong of course because my subnet mask was which
    meant I calculated the subnets wrong.

    As you can imagine it took me a while to write all of this and since then I
    have moved further into the book and found more errors which again have gone
    From what I understand the whole networking part of the book was originally
    in another book called “Network Essentials†about 10 years ago and this was a
    separate exam by MS. They decided to phase out this exam and integrate the
    knowledge and exam questions into this exam. It looks like it hasn’t been
    updated in 10 years either though!! Here is an example which is clearly wrong
    (but may have been right 10 years ago):
    You have a IP address, what could be the cause of this?
    It turns out the answer was a network cable was unplugged.
    This is no longer correct...especially in XP and 2003 (which is what the
    exam is about!!). Now it says the media is disconnected and your IP shows as About 10 years ago though NT maybe Win98 or even Win2k did show this
    (but I can’t remember to be exact).

    This is a joke and the training material needs a serious overhaul. The test
    questions you get in these books and other books come directly from MS
    because as I have seen them similar in the exams. No exam questions should be
    vague. If there are clearly different ways to answer a question then MS
    should give more details, at least hinting how they want it answered. You
    could quite easily fail because of the lack of details given in the questions.
    I am sure I am not the first to see this and I would like to hear other
    people’s opinions on this.

    Thanks reading.
    Graham Allen, Sep 15, 2009
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  2. Graham Allen

    Graham Allen Guest

    Can't edit my original post.
    I meant the book says Method 1 and not Method 2 (typo error) when I am
    talking about first and last subnets being invalid.
    Graham Allen, Sep 15, 2009
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