How to distinguish abc class ip addresses

Distinguishing method: 1. Class A IP address, the first number is the network number, and the remaining three numbers are the numbers of the local computer; 2. Class B IP address, the first two numbers are the network number ; 3. Class C IP address, the first three numbers are the network number, and the remaining number is the local computer number.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

1. Class A IP address:

A Class A IP address means that among the four numbers in the IP address, the first number is the network number, and the remaining three numbers are is the number of the local computer.

If the IP address is represented in binary, the Class A IP address consists of a 1-byte network address and a 3-byte host address. The highest bit of the network address must be "0".

The length of the network identifier in a Class A IP address is 8 bits, and the length of the host identifier is 24 bits. The number of Class A network addresses is small, with 126 networks, and each network can accommodate more than 1,600 hosts. Thousands of units.

2. Class B IP address

A Class B IP address means that among the four numbers in the IP address, the first two numbers are the network number. If the IP address is represented in binary, the Class B IP address consists of a 2-byte network address and a 2-byte host address. The highest bit of the network address must be "10".

The length of the network identifier in the Class B IP address is 16 bits, and the length of the host identifier is 16 bits. Class B network addresses are suitable for medium-sized networks. There are 16384 networks, and each network can accommodate The number of computers is more than 60,000.

3. Class C IP address

A Class C IP address means that among the four numbers in the IP address, the first three numbers are the network number, and the remaining number is the local number. The computer's number.

If the IP address is represented in binary, the Class C IP address consists of a 3-byte network address and a 1-byte host address. The highest bit of the network address must be "110".

The length of the network identifier in a Class C IP address is 24 bits, and the length of the host identifier is 8 bits. There are more Class C network addresses, with more than 2.09 million networks. Suitable for small-scale local area networks, each network can only contain up to 254 computers.

Extended information:

IP address refers to the Internet Protocol Address (English: Internet Protocol Address, also translated as Internet Protocol Address), which is the IP Address abbreviation.

The IP address is a unified address format provided by the IP protocol. It assigns a logical address to each network and each host on the Internet to shield the differences in physical addresses. There are still some IP proxy software, but most of them charge a fee.

Some other IP addresses:

1. Class D IP address:

Class D IP address was historically called multicast address (multicast address), that is, multicast address. In Ethernet, a multicast address names a set of stations on the network that should receive a packet.

The highest bit of the multicast address must be "1110", ranging from 224.0.0.0 to 239.255.255.255.

2. Special URL:

(1). The address where each byte is 0 ("0.0.0.0") corresponds to the current host;

( 2). An IP address in which each byte in the IP address is 1 ("255.255.255.255") is the broadcast address of the current subnet;

(3). Any byte in the IP address Class E IP addresses starting with "11110" are reserved for future and experimental use;

(4). The IP address cannot start with the decimal "127". The number in this type of address is 127.0. 0.1 to 127.255.255.255 are used for loop testing. For example: 127.0.0.1 can represent the IP address of the local machine. Use "http://127.0.0.1" to test the Web server configured in the local machine;

(5). The first 8-bit group of the network ID cannot be set to all "0". All "0" indicates the local network.

For more computer-related knowledge, please visit the FAQ column!

The above is the detailed content of How to distinguish abc class ip addresses. For more information, please follow other related articles on the PHP Chinese website!