IP addresses are divided into classes so that they can be assigned to a particular business, government or other entity based on size and need. There are five IP classes plus certain special addresses:
Special addresses:
Default Network - The IP address of 0.0.0.0 is used for the default network.
Loopback - The IP address 127.0.0.1 is used as the loopback address. This is used by the computer to send a message back to itself, usually for troubleshooting and network testing.
Broadcast - Messages intended for all computers on a network are sent as broadcasts. These messages use the IP address 255.255.255.255.
Classes:
Class A - These are reserved for very large networks, like a huge international company. Class A networks account for half of the total available IP addresses. The first set of numbers in the IP address for this class are 1-126.
Class B - These are reserved for medium sized networks, like a university campus. The first set of numbers in the IP address for this class range from 128 to 191.
Class C - These are typically used for small businesses. The first set of numbers in the IP address for this class range from 192 to 223.
Class D - These are used for multicasts. A multicast enables a message to be transmitted to a group of hosts, instead of having to address and send the message to each group member individually.
Class E - These are used for experimental purposes.
Special addresses:
Default Network - The IP address of 0.0.0.0 is used for the default network.
Loopback - The IP address 127.0.0.1 is used as the loopback address. This is used by the computer to send a message back to itself, usually for troubleshooting and network testing.
Broadcast - Messages intended for all computers on a network are sent as broadcasts. These messages use the IP address 255.255.255.255.
Classes:
Class A - These are reserved for very large networks, like a huge international company. Class A networks account for half of the total available IP addresses. The first set of numbers in the IP address for this class are 1-126.
Class B - These are reserved for medium sized networks, like a university campus. The first set of numbers in the IP address for this class range from 128 to 191.
Class C - These are typically used for small businesses. The first set of numbers in the IP address for this class range from 192 to 223.
Class D - These are used for multicasts. A multicast enables a message to be transmitted to a group of hosts, instead of having to address and send the message to each group member individually.
Class E - These are used for experimental purposes.