# 70-297 how many subnets?

Discussion in 'MCSE' started by Emiel Lieshout, Nov 22, 2004.

1. ### Emiel LieshoutGuest

Hello,

I'm preparing for the 70-297 exam.
I know now how to calculate how many hosts there are in a subnet.
But i need someone to explane to me how to calculate how many subnet's there
are for instamce in a 255.255.0.0/15 subnet.

I've used the official microsoftpress book, but just don't get it!
Maybey one of you can explain or direct me to a site or sent me a word or
pdf-file in wich things are explained.

Kind regards,

Emiel Lieshout

Emiel Lieshout, Nov 22, 2004

2. ### GuestGuest

10, I think but i could be guessing is it 10? i hope im
right and it is 10, OH polz be 10, come on luckey 10
>-----Original Message-----
>Hello,
>
>I'm preparing for the 70-297 exam.
>I know now how to calculate how many hosts there are in a

subnet.
>But i need someone to explane to me how to calculate how

many subnet's there
>are for instamce in a 255.255.0.0/15 subnet.
>
>I've used the official microsoftpress book, but just

don't get it!
>Maybey one of you can explain or direct me to a site or

sent me a word or
>pdf-file in wich things are explained.
>
>Kind regards,
>
>Emiel Lieshout
>
>
>.
>

Guest, Nov 22, 2004

3. ### molsonexpertGuest

"Emiel Lieshout" <> wrote in message
news:41a1c1aa\$0\$767\$...
> Hello,
>
> I'm preparing for the 70-297 exam.
> I know now how to calculate how many hosts there are in a subnet.
> But i need someone to explane to me how to calculate how many subnet's

there
> are for instamce in a 255.255.0.0/15 subnet.
>
> I've used the official microsoftpress book, but just don't get it!
> Maybey one of you can explain or direct me to a site or sent me a word or
> pdf-file in wich things are explained.
>
> Kind regards,
>
> Emiel Lieshout
>
>

try these resources:

http://www.learntcpip.com/

http://www.learntosubnet.com/

http://www.petri.co.il/subnetting_table.htm

steve.

molsonexpert, Nov 22, 2004
4. ### KurtGuest

First of all 255.255.0.0 is a /16 network - not a /15. But in its simplest
terms (since you know how to calculate the number of hosts in a subnet) you
can determine the number of subnets by taking the total number of hosts on
the whole network divided by the number of hosts in each subnet. So if you
have a class B network, say 172.16.0.0 /16 (subnet mask 255.255.0.0) that
is a total of 65536 hosts (including network and broadcast). If you break it
up into /24 subnets (255.255.255.0) you have 256 hosts per subnet. If you
then divide the total number of hosts by the number of hosts per subnet
(65536/256) you get 256 subnets.

"Emiel Lieshout" <> wrote in message
news:41a1c1aa\$0\$767\$...
> Hello,
>
> I'm preparing for the 70-297 exam.
> I know now how to calculate how many hosts there are in a subnet.
> But i need someone to explane to me how to calculate how many subnet's

there
> are for instamce in a 255.255.0.0/15 subnet.
>
> I've used the official microsoftpress book, but just don't get it!
> Maybey one of you can explain or direct me to a site or sent me a word or
> pdf-file in wich things are explained.
>
> Kind regards,
>
> Emiel Lieshout
>
>

Kurt, Nov 23, 2004
5. ### KurtGuest

Another way is to count how many bits you add to the right of the original
network. The number of subnets doubles with each bit.

So once again starting with a /16:
add 1 bit (/17) and you have 2 subnets
add 2 bits (/18) and you have 4 subnets
add 3 bits (/19) and you have 8 subnets
etc.
..
..
..

"Kurt" <> wrote in message
news:...
> First of all 255.255.0.0 is a /16 network - not a /15. But in its simplest
> terms (since you know how to calculate the number of hosts in a subnet)

you
> can determine the number of subnets by taking the total number of hosts on
> the whole network divided by the number of hosts in each subnet. So if you
> have a class B network, say 172.16.0.0 /16 (subnet mask 255.255.0.0) that
> is a total of 65536 hosts (including network and broadcast). If you break

it
> up into /24 subnets (255.255.255.0) you have 256 hosts per subnet. If you
> then divide the total number of hosts by the number of hosts per subnet
> (65536/256) you get 256 subnets.
>
> "Emiel Lieshout" <> wrote in message
> news:41a1c1aa\$0\$767\$...
> > Hello,
> >
> > I'm preparing for the 70-297 exam.
> > I know now how to calculate how many hosts there are in a subnet.
> > But i need someone to explane to me how to calculate how many subnet's

> there
> > are for instamce in a 255.255.0.0/15 subnet.
> >
> > I've used the official microsoftpress book, but just don't get it!
> > Maybey one of you can explain or direct me to a site or sent me a word

or
> > pdf-file in wich things are explained.
> >
> > Kind regards,
> >
> > Emiel Lieshout
> >
> >

>
>

Kurt, Nov 23, 2004
6. ### EricGuest

I couldn't have explained it better
"Kurt" <> wrote in message
news:...
> First of all 255.255.0.0 is a /16 network - not a /15. But in its simplest
> terms (since you know how to calculate the number of hosts in a subnet)
> you
> can determine the number of subnets by taking the total number of hosts on
> the whole network divided by the number of hosts in each subnet. So if you
> have a class B network, say 172.16.0.0 /16 (subnet mask 255.255.0.0) that
> is a total of 65536 hosts (including network and broadcast). If you break
> it
> up into /24 subnets (255.255.255.0) you have 256 hosts per subnet. If you
> then divide the total number of hosts by the number of hosts per subnet
> (65536/256) you get 256 subnets.
>
> "Emiel Lieshout" <> wrote in message
> news:41a1c1aa\$0\$767\$...
>> Hello,
>>
>> I'm preparing for the 70-297 exam.
>> I know now how to calculate how many hosts there are in a subnet.
>> But i need someone to explane to me how to calculate how many subnet's

> there
>> are for instamce in a 255.255.0.0/15 subnet.
>>
>> I've used the official microsoftpress book, but just don't get it!
>> Maybey one of you can explain or direct me to a site or sent me a word or
>> pdf-file in wich things are explained.
>>
>> Kind regards,
>>
>> Emiel Lieshout
>>
>>

>
>

Eric, Nov 25, 2004