Attached are some GREAT articles on how to Subnet a Network. But first here is an overview of what subnetting is.
Part I: For the IP Beginner
IP Network AddressesTo understand network IP addressing, let’s take a look at postal addresses. Every building
must have its own unique address in order for mail to be delivered. An address consists of
different parts such as the street, number, and city. In a network, every device must have
its own unique IP address. That is, every network device (printer, server, router, etc.)
must be identified with a separate IP address.
Many Devices or HostsUsing the postal example, think about an apartment building. In order for the mail to
arrive at the right apartment, each apartment must have its own unique identifier
(apartment number) in addition to the street name and address.
With IP addresses, an organization is assigned a unique IP network, such as 192.168.1.0,
but a single IP address must be assigned for each network device. For example, let's
assume that ABC company has 5 devices in one of their buildings that need IP addresses,
and that ABC is assigned the network address 192.168.1.0. The IP addresses could be
assigned as follows:
Device 1 (router): 192.168.1.1
Device 2 (office printer): 192.168.1.2
Device 3 (Ms. Chung's laptop): 192.168.1.3
Device 4 (Receiptionist's computer): 192.168.1.4
Device 5 (company server): 192.168.1.5
Hosts .1, .2, .3, .4, and .5 are all on the 192.168.1 network, just as apartments 1, 2, 3, 4,
and 5 might be located in the apartment building at 123 First Street.
When you see an IP address, you will always see another number associated with it that
looks something like one of the following:
♦ 255.255.255.0
♦ 255.255.0.0
♦ 255.0.0.0
This number is called the
subnet mask. A subnet mask is used to show which portion of
the IP address identifies the network and which portion identifies a specific host on the
network. This may seem unnecessary at first since the first three numbers of an IP address
starting from the left (such as 192.168.1) always identify the network, and the last number
(such as .1) always identifies an individual device in networks like the one in our example,
which is called a standard Class C network. However, this is not true for other networks.
That's why subnet masks are used to differentiate the network portion of the address from
the host portion. The following table shows the subnet mask 255.255.255.0, which is
always the subnet mask for a standard Class C network, applied to one of our example
addresses. Notice how the mask reveals which portion of the string 192.168.1.1 is the
individual host address.
NOTE: Class C addresses have a number from 192 to 223 in the first octet.
Network portion Host portion
192 168 1 1
255 255 255 0
The number 255 indicates that the corresponding section of the address is part of the
network address. The 0 indicates that the corresponding section is the host portion of the
address.
This document and the Subnet game refer only to Class C networks. Once you
understand IP addressing for Class C networks, it will be much easier for you to
understand IP addressing for any network.
File Attachment(s):
Subnetting a Network.pdf (103kb) downloaded 12 time(s).
Adam D. Technology
Adam Dellos
adellos@adamdtechnology.com(520) 591-3891
http://www.adamdtechnology.com"We give you twice the work in half the time and leave you with a peace of mind!"
