1. Subnetting
Subnetting is a method for getting the most out of the limited 32-bit IP addressing space. With any address class, subnetting provides a means of allocating a part of the host address space to network addresses, which lets you have more networks. The part of the host address space allocated to new network addresses is known as the subnet number.
The InterNIC assigned the University of Windsor one class B Network address, which is with network number part The Host number part is left to be assigned at the discretion of the owner of the network number (local management - The Computing Services)

2. Subnetting

3. Subnetting
In class B IP address, the 2 right-hand bytes assigned for the host
number, can be subdivided into 254 subnetworks and 254 hosts to
each subnetwork number.
Which bits in the host address bytes will be applied to subnet
addresses and which to host addresses is determined by a subnet
mask, or netmask.(/etc/netmasks)
The netmask can be applied to an IP address using the bitwise
logical AND operator.
If a netmask (or FF.FF.FF.00) is applied to the
address (or 89 CF C0 03), the result is a network
number
i.e.:     & =
or,    89 CF C0 03 & FF FF FF 00
= 89 CF C0 00.

4. Subnetting In binary form, the operation is:
(IP address ) AND (netmask)
(masked number)
Now the system (router or server) will look for a network number of instead of a network number of , then the router (or the server) will now locate the host, (workstation) , from its table, and adds the corresponding machine number, to arrive to  To increase the host number from 254, a different mask number could be used for less subnetworks and more hosts

5. Subnetting