# Determining network size requirements in slash notation terms

• ### Question

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Is anybody can give me step by step explanation?

Thank you !

Monday, March 3, 2014 1:44 PM

• If you want ot learn how to do this yourself, subnet calculator (as mentioned by Denis Cooper) will not work for what you need.  Actually, its fairly easy.  If you are not aware of 'binary', you should familiarize yourself with that.  Then:

You have 8 Bits per Octet in your subnet:

example

192.168.0.1

which represented in binary is as:

11000000.10101000.00000000.00000001

So then take the first 27 bits which would be the first 3 octets + the first 3 bits in the last octet:

11000000.10101000.00000000.000

leaving the last 5 bits for your hosts: 00001

Here's a tutorial that should help:

Monday, March 3, 2014 2:04 PM

### All replies

• The easiest way to work these out is to us a subnet calculator. You can find one here

http://www.subnet-calculator.com/subnet.php?net_class=A

There are also plenty of tutorials out their to show you how to learn about subnetting

http://www.subnetting-secrets.com/

Regards,

Denis Cooper

MCITP EA - MCT

Help keep the forums tidy, if this has helped please mark it as an answer

Monday, March 3, 2014 1:50 PM
• If you want ot learn how to do this yourself, subnet calculator (as mentioned by Denis Cooper) will not work for what you need.  Actually, its fairly easy.  If you are not aware of 'binary', you should familiarize yourself with that.  Then:

You have 8 Bits per Octet in your subnet:

example

192.168.0.1

which represented in binary is as:

11000000.10101000.00000000.00000001

So then take the first 27 bits which would be the first 3 octets + the first 3 bits in the last octet:

11000000.10101000.00000000.000

leaving the last 5 bits for your hosts: 00001

Here's a tutorial that should help: