Q. Are there tools available to help you subnet a network?
A. There are numerous downloadable and Web-enabled tools that will help you subnet a network. I've used the calculator at http://www.subnet-calculator.com, and in particular the classless version at http://www.subnet-calculator.com/cidr.php. It's simple to use and it lets you enter an IP address, the required subnet mask, or just the number of bits to use, and it will display the network and the address ranges to be used for clients. Alternatively, you can tell it how many networks or host addresses you need, and it will set the subnet mask accordingly.