|  | 10.4 | IP Address Classes
| 10.4.4 | Converting decimal IP addresses to binary equivalents.

In order to convert decimal IP addresses to binary numbers you must know the decimal values of each of the 8 bits in each octet. Starting with the bit that is on the left side of the octet, the values start at 128 and are reduced by half each time you move 1 bit to the right, continuing to a value of 1 on the right side of the octet.. The conversion below illustrates the first octet only.

Example:
Convert the first octet of 192.57.30.224 to a binary format.

128 | +64 | +0 | +0 | +0 | +0 | +0 | +0 | = | 192
27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 |  |
1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | = | 11000000

The first step is to select the octet on the far left and determine whether the value is greater than 128. In this instance (192), it is. Then place a 1 in the first bit and subtract 128 from 192. The remainder is 64. The value of the next bit is 64, which is equal to the value of the remainder, so that bit would be 1 as well. Subtract 64 from 64. The remainder is 0, therefore the remaining bits would all be 0. The binary number for the first octet would be 11000000.

Exercise:
Convert the remaining octets (57, 30, 224), in the IP address, to binary format.