802.11a or b faster?

Megadeth4168

I was taking one of my practice exams and I had this question come up and I picked 802.11a because it can reach speeds of 54mbs unless I'm mistaken.... The practice test says that 802.11b was the fastest of the options listed.

Am I wrong or reading the question wrong or is the practice test wrong?

Vask3n

Let me guess....Preplogic?

I had that same issue. As far as I can recall, 802.11a is on a different band than 802.11b, but generally 802.11a is faster, at a max of 54Mbps. I guess Preplogic was trying to ask what the fastest in the 2.4Ghz range was, or something....Had the same issue, just remember to select 802.11b when retaking the exam

Webmaster

www.techexams.net/technotes/securityplus/wireless.shtml

Megadeth4168

Vask3n wrote:

Let me guess....Preplogic?

I had that same issue. As far as I can recall, 802.11a is on a different band than 802.11b, but generally 802.11a is faster, at a max of 54Mbps. I guess Preplogic was trying to ask what the fastest in the 2.4Ghz range was, or something....Had the same issue, just remember to select 802.11b when retaking the exam

Mike Meyers Passport practice exams that came with the book actually. There was nothing in the question that specified in which range so I guess it was just a poorly written question. For the real exam Im guessing I should choose 802.11a unless otherwise the freq. range is specified.... right....

Vask3n

I guess Preplogic "borrowed" a question from Mr. Meyeres then

Don't worry, I highly doubt there would be any questions THAT confusing on the exam, or maybe it was just my draw of questions that makes me think that.

Megadeth4168

I hope I wont questions that are lacking proper info to answer the question fully....

Here is another one UNLESS I am wrong and in which case would be willing to admit I am wrong but the question was as follows.

Which of the following are valid nonroutable private address.
10.0.0.0
172.20.0.0
198.162.0.0

I looked at this and said both A and B should work however the answer according to them is that only A is correct... Maybe I'm wrong but I thought that the Class B Private address range was 172.16 thru 172.31 in which case the 172.20 would work as an answer correct?

Webmaster

nonroutable? None of the above. Protocols can be nonroutable... And all the answers listed are from the private address ranges.

More importantly, this is 'not' a Security+ related question.

Megadeth4168

Non-Routable or sometimes referrred to that way....
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094831.shtml
http://www.pku.edu.cn/academic/research/computer-center/tc/html/TC0305.html
Mostly because they are not unique addresses.

I think it is better as a Network+ question and not so much a Security+ question. So I do agree with that.

The last one should be 192.168 to be correct not 198.162... I actually read it wrong at first when I took that test and almost clicked that one as well but then saw that they switch the numbers slightly.

Webmaster

"198.162.0.0" nice one, read right over that...

Ah yes, different context (NAT)... I'm used to calling that non-routed, or better, 'translated' (referring to the connection) instead of non-routable. You can't route that address on to public networks for example, non-routable as in they have to be translated. It's the same as I described in the second paragraph of my Network+ Internet Connections TechNotes:
www.techexams.net/technotes/networkplus/internetconnections.shtml
'routed vs. translated connections'

Which of the following are valid nonroutable private address?

So that's redundant, which actually makes it a good question combined with the 8 and 2 swapped in the address.

Danman32

I wish these practice tests would get a peer review before being published. I have yet to see one that didn't clearly have mistakes.

Private address range could be brought up in a Security+ exam, as using private address ranges increases security on your network, since those addresses can't be directly accessed from the internet.

I too got stung by 192.162.0.0. That's my biggest problem with these tests; I get fooled too easily.

Megadeth4168

Webmaster wrote:

"198.162.0.0" nice one, read right over that...

Ah yes, different context (NAT)... I'm used to calling that non-routed, or better, 'translated' (referring to the connection) instead of non-routable. You can't route that address on to public networks for example, non-routable as in they have to be translated. It's the same as I described in the second paragraph of my Network+ Internet Connections TechNotes:
www.techexams.net/technotes/networkplus/internetconnections.shtml
'routed vs. translated connections'

Which of the following are valid nonroutable private address?

So that's redundant, which actually makes it a good question combined with the 8 and 2 swapped in the address.

I did actually know what you were saying, I just thought I would clarify what they meant as Non-routable incase there was any confusion. It is a very tricky question and somewhat redunant as you pointed out.

It's just funny when you click the explaination button it mentions the Private IPs as
10.0.0.0
172.16
192.168

It fails to mention the range like 172.16 - 172.31 so For the time being I actually marked myself as correct on that question. I'm thinking the real test may not have so many little mistakes like that. I'm hoping at least.

Danman32: I too wish they would put a little more effort into peer review before releasing these tests. The great thing I love about this site is that the Webmaster is very active and if someone does catch something on a practice test here it is more likely to be fixed right away.

Webmaster

Megadeth4168 wrote:

Danman32: I too wish they would put a little more effort into peer review before releasing these tests. The great thing I love about this site is that the Webmaster is very active and if someone does catch something on a practice test here it is more likely to be fixed right away.

Thanks. Being annoyed by flat out incorrect information in IT certification material is actually one of the reasons I started writing. It 'is' very difficult to find a book or set of practice questions that is entirely accurate. Over the past four years I, and others who wrote for us, made less mistakes than most of the commercial study material providers. And most of the few we made include typos and mixed-up ABCDs when I port them to our test engine (which is in raw XML). Actually technical errors we make very little. That's not because we are such great techies compared to the writers that work for commercial companies. We just take some extra time, we don't need to finish a complete set of practice questions or TechNotes PDF by next month to compete with another company. Our motto has always been 'quality over quantity'. I use proofreaders, SMEs, spend more time on research and fact checking than actually typing words, even for the topics I have years of experience with, had to study for several exams etc. So do the better commercial study material providers, but some of them really do need to (and you'd imagine they can) put some extra money in proofreaders and SMEs (subject matter experts, just in case...).

Nobody is perfect though, humans make mistakes too. What's important to realise is that the eventual text is never a perfect reflection of what the author knows or can. If that would be the case you'd find a lot more quality commercial and free study material. Being able to understand topics, answer questions about them, and being able to configure, design, install, and troubleshoot a certain product or technology doesn't directly is something different than writing it down and be 100% accurate. When you perform a task at work the result may be perfect, but the road to it often isn't. You make mistakes and correct yourself along the way. Not trying to brag about myself here, just reasoning why there are hardly any perfect books (if any, as lots of things are not accurate under all circumstances/ in every context). But here's a good example:

Michael Pastore, the author of Sybex's Security+ guide, likely knows that L2TP uses port 1702, and not port 22, which he in a following paragraphs correctly assigns to SSH. This is error was in the first edition (page 126), not sure, but I think it's in the second as well, even though they already had it on their site in the errata section, and I reported it to them aftert they send me a review copy of the first edition. The technical editor for the book is the author of Sybex's Network+ study guide. Surely he knows l2tp doesn't use port 22. Somewhere along the process from writing to press something went wrong. I can take a couple of these in commercial products. I'm more worried about things as 'Appletalk is not routable'. I've seen those a lot over the past decade, putting limits on technologies that do not apply under all circumstances, or are just incorrect.

Another recent example from myself, reported by Danman32, is the use of 'ports' instead of 'protocol' id in the IPSec section of my Security+ TechNotes. I've known that for probably about 3 or 4 years. From theory and practice. And if I'm not 'mistaken', someone actually reported the same thing long ago in regards to a Sec+ practice question or other TechNotes.

I guess it's a lot like the 198.162.0.0, but with something you wrote yourself. I'm sure the people who worked on that Sybex guide read right over the '22' several times.

Ok... I didn't plan to write 'that' much... one more thing though, there are two positive sides to it:
- It forces you to fact check everything yourself. And I mean everything. You should never rely on one source anyway (whether it's a book, coworker, an error message in Windows, etc.), and reading the same topics multiple times, written slightly differently will make those errors stand out 'and' make things stick better.
- You can learn from other's mistakes in addition to your own. Learning from mistakes makes things stick even better. You're not likely to forget the details about the error you found anytime soon.

Megadeth4168

Well said on everything
I went and looked at me eBook for the Sybex book (2nd edition) sure enough there it was. Hehe, I must of missed that myself when reading through the book the first time.

Danman32

Yes, I remember reading poart 22 versus 1702.

What gets me the most is when you take a practice test, get questions marked wrong so that you get a low overall score, only to discover you were actually right about a few.

For example, in Sybex practice exam for 293 with regard to subnetting. One question had you subnet for at least 2048 hosts, which correctly required a subnet mask of 21 bits. The very next question, you needed 8198 hosts and 6 subnets, but they marked the right answer as still requiring 21 bits instead of the correct 19.

"It should be 192.168.1.0/21 since you need 6 subnets and 8196 hosts."
Uh, you don't get that many hosts with 21 bits.

Fortunately, I've been in the industry for quite a while, so I can flag in my head what is written wrong. Woe to the one who is not as experienced and gets misinformed.