TCP/IP Protocol Class A Class B Class C Class D address

TCP (Transmission Control Protocol): responsible for connecting to the remote host IP (Internet Protocol): responsible for addressing and sending packets to the location where they are located

IP Address: it is the logical address used by the network layer of TCP/IP to identify hosts in the network. It can uniquely identify a host in Interent.

An IP address is a 32-bit binary address. Each IP address is divided into four segments (eight bits per segment). An IP address consists of a network address and a host address in the network.

(1) Class A addresses use the first eight digits to identify the network address, and the third eight digits to identify the host address (range: 1.0.0.0 ~ 126.0.0.0)

(2) Class B addresses use two 8-bit network addresses, and the other two constitute the host number (range: 128.1.0.0 ~ 191.254.0.0)

(3) Class C addresses use three 8-bit network addresses and one 8-bit host number (range: 192.0.1.0 ~ 223.0000254.0)

(4) Class D address is used for multicast in an IP Network (range: 224.0.0.0 ~ 239.00000000254)

(5) Class E address: Reserved (range: 240.0.0.0 ~ 255.255.255.255)

Subnet Mask:

The subnet mask (subnet mask) is also known as the network mask, address mask, and subnetwork mask. It is used to indicate which bits of an IP address identify the subnet where the host is located, and the bit masks that identify the host. The subnet mask cannot exist independently. It must be used together with the IP address. The subnet mask has only one function, namely dividing an IP address into a network address and a host address.

For example:

To define the subnet mask, follow these steps: A. determine which group addresses are used by us. For example, if the requested network is "210.73.a. B", the network address is a class c ip address, the network ID is "210.73.a", and the host ID is "B ". B. Define the subnet mask based on the number of subnets required and the number of subnets that may be extended in the future. For example, we need 12 subnets and 16 in the future. Determine the subnet mask with the first four digits of the fourth byte. The first four digits are set to "1", that is, the fourth byte is "11110000". This number is now called the New Binary subnet mask. C. Set each bit of the corresponding initial network to "1", that is, the first three bytes to "1". Then, the intermittent binary form of the subnet mask is: "11111111.111111.1111111111.1111110000 ". D. Convert the number into a break decimal format: "invalid decimal limit 240 ".

Note: The number of subnet masks determines the number of subnets and the number of hosts in each subnet. Before defining the subnet mask, you must determine the number of subnets and the number of hosts used.

Practical Significance: With the development of the Internet, more and more networks are generated. Some networks have several hundred and some have only a few partitions. This wastes a lot of IP addresses, so we need to divide subnets. Using subnets can improve the efficiency of network applications.

 

 

TCP/IP Protocol Class A Class B Class C Class D address