To truly understand how to derive IP subnet masks and apply them
to addresses, you must understand binary numbers and how to
convert them to decimal numbers. Let's start with something that
we're all pretty comfortable with--namely, decimal (base 10)
numbers. Each digit in a decimal number stands for a different
power of 10. You interpret the number 7836, for example, as
follows: You interpret binary (base 2) numbers the same way as
you do decimal numbers, except that each column of a binary
number represents a different power of 2 rather than 10. Let's
first review the powers of 2 (we're only going to go as far as
we need to for an 8-bit byte because IP addresses have 8-bit
bytes). Given this information, you can convert the binary
number 11010011 to decimal as follows. IP Addresses and Subnet
Masks You can apply what you know about binary numbers to IP
addresses and subnet masks. IP addresses are 32 bits, or four
8-bit bytes, in length. Although computers store IP addresses in
binary format, you typically w