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Re: Performing Summarization [1:14212] posted 11/19/2003
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sorry guys..i still dun understand the explanation on this question

1)You are given this address space :172.16.5.0/25 .You need one
> > network
> with
> > 64 hosts and two with 30 hosts .What are the most specific subnet mask
>
> > values to use ?
> >
> > a)/25 and /26
> > b)/26 and /27
> > c)/27 and /28
> > d)none of the above...
> >

i have re-read ip addressing....does that means that with a /25 subnet i
have (2 to the power of 1)2 subnet and /26 i have 4 and /27 i have 8..am i
right here?


""Richard Deal""  wrote in message
news:200311181952.hAIJqitS023092@xxxxxxxxxxxxxxxxx
> Larry,
>
>
>
> /25 is 126 host addresses, with a total of 128; /26 is 62 host addresses,
> with a total of 64. Remember that each subnet has a network number and a
> broadcast address, so you lose two host addresses. It's important to keep
in
> mind that there is a difference between "number of hosts" and "number of
> addresses".
>
>
>
> Cheers!
>
>
> --
>
> Richard A. Deal
>
> Cisco Test Prep author for QuizWare, providing the most comprehensive
Cisco
> exams on the market (www.quizware.com)
>
> Author of CCNA Cisco Certified Network Associate Study Guide (Exam
640-801),
> CCNP BCMSN Exam Cram 2, Cisco PIX Firewalls, CCNA Secrets Revealed!, CCNP
> Remote Access Exam Prep, CCNP Switching Exam Cram, and CCNP Cisco LAN
Switch
> Configuration Exam Cram
>
> Visit my home page at http://home.cfl.rr.com/dealgroup/
>
>
>
>
>
> ""Larry Letterman""  wrote in message
> news:200311181929.hAIJTwJj019803@xxxxxxxxxxxxxxxxx
> > A /25 is 128 host address's....
> > A /26 is 64 host address's...
> >
> >
> > Larry Letterman
> > Cisco Systems
> >
> >
> >
> >
> > -----Original Message-----
> > From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of
> > Richard Deal
> > Sent: Tuesday, November 18, 2003 10:46 AM
> > To: associate@xxxxxxxxxxxxxx
> > Subject: Re: Performing Summarization [1:14212]
> >
> >
> > JL,
> >
> > I'm the author :-). Please see my comments inline below.
> >
> > ""J L""  wrote in message
> > news:200311181222.hAICM2xu006271@xxxxxxxxxxxxxxxxx
> > > i got a question from Mr Richard Deal'a book from page 523(chapter 12)
> > >
> > > 1)You are given this address space :172.16.5.0/25 .You need one
> > > network
> > with
> > > 64 hosts and two with 30 hosts .What are the most specific subnet mask
> >
> > > values to use ?
> > >
> > > a)/25 and /26
> > > b)/26 and /27
> > > c)/27 and /28
> > > d)none of the above...
> > >
> > > my ANSWER is "B" but wrong why?
> > >
> >
> > Notice the first part--you need 64 HOST addresses--this requires a /25
> > bit mask and therefore there is no address space left for the other two
> > subnets since you originally started out with a /25 mask; therefore,
> > answer D is correct.
> >
> > > 2)You are given a Class C network,192.168.1.0/24.You need three
> > > networks with 60 hosts and two networks with 30 hosts.What are the
> > > sybnet mask
> > values
> > > you could use ? (Choose all the correct answers .)
> > >
> > > a)255.255.255.128 n 255.255.255.192
> > > b)255.255.255.224 n 255.255.255.240
> > > c)255.255.255.192 n 255.255.255.224
> > > d)none of these
> > >
> > > my ANSWER is "A" but wrong also.....why?
> > >
> > The answer is b. A 60 host subnet needs a 255.255.255.192 mask. This
> > results in 4 subnets. take the 4th one and split it in two with the
> > 255.255.255.224 mask, resulting in two subnets of 30 hosts each. PLEASE
> > REMEMBER that using the first and last subnet ARE permissible unless
> > specifically stated!!!! Sometimes the real exam might not say one way or
> > another, but you'll be able to deduce this from the answer. Poor on
> > Cisco's part to do this, since it is perfectly legal to use "subnet
> > zero". Heck, it's enabled by default on 12.x IOS versions!
> >
> > If you're having problems with VLSM, please make sure you revisit the
> > chapter on IP addressing and subnetting. If you don't understand
> > subnetting and have it down cold, then VLSM will beyond your grasp. I
> > recommend that you develop a bunch of questions on your own, or use the
> > ones on the CD, and practice, practice, practice. Use the subnet
> > calculator on the CD to verify your answers, as well as to help you get
> > a better understanding of the process.
> >
> > Cheers!
> >
> > Richard A. Deal
> > > Thanks a lot.
> > > JL
> > your subscription, read the directions on:
> > http://www.groupstudy.com/list/Associates.html




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