As the number of devices in your network expands, you may find yourself running out of IP addresses available to your DHCP server. This can particularly be a problem with all the new kinds of devices commonly being added to networks, such as smart phones and tablets.
Fortunately, there’s a simple way to expand a subnet; just lower the number in your subnet mask. For example, changing from 255.255.255.0 to 255.255.254.0 doubles the number of available IP addresses. This is known as resubnetting.
Keep in mind that adding too many devices per subnet can decrease performance. Hence, at some point, it may make sense to add separate subnets for different kinds of devices.
To find out more about increasing IP addresses on a Windows DHCP Server, consult the following article: