What can I do if I know the ip address? Tell me in detail.

Role of IP address: IP address is used to identify the address of the host. The network consists of several hosts. Every host must have a globally unique IP address, just like the telephone number in our life. Each phone can only have a globally unique phone number. Broadly speaking, hosts can be workstations, servers and routers working in the network. IP addresses are usually expressed in decimal and consist of four numeric fields separated by commas.

Composition of 1.IP address: IP address consists of two parts, as shown in figure 1. The first part is the network number, followed by the host number. The network number determines the location information of the host, which is equivalent to the area code of our telephone number, and the host number is the address of the machine. The IP address plus subnet mask is the real address of the host on the network. This is the same as our telephone number, and it is also composed of area code and telephone number. The principle of IP address is based on binary form, but when we use it, it is all converted into decimal, and only when calculating subnet mask, it is expressed in binary form.

2. Classification of IP addresses: IP addresses are generally classified into three categories: A, B and C. We take the IP address w.x.y.z as an example to illustrate the classification of the three types of IP addresses: when the value of W is between 1 and 126, the IP address is Class A, and the default subnet mask is 255.0.0.0. When the value of W is between 128- 19 1, the IP address is Class B and the default subnet mask is 255.255.0.0. When the number of W is between 192-223, the IP address is Class C, and the default subnet mask is 255.255.255.0.

3. Several regulations of international NIC organization: 127.0.0. 1 is the IP address reserved for loopback test of this machine. 192.X.X.X and 10.x.x are reserved addresses of the local area network. An address with all host bits of 1 is the broadcast address of the network, and an IP address with all host bits of 0 refers to the network itself.

4. Reasonable choice of IP address: What kind of IP address is used directly determines how many machines can be accommodated in this subnet. So we can choose a reasonable IP address according to our own network size. Let's look at the IP address of Class C, 192. 168. 1. X, and the last value, we don't want to use decimal analysis and convert it into binary. There are eight binary numbers, that is, we need to use 0 and 1 to make an eight-bit non-repeating number. By combining and arranging, 28 different numbers can be generated. Because the combination of all zeros is the network itself and cannot be used, and the combination of all zeros is the broadcast address, there will be 28-2 different values, that is, 254 different values, which determines that the Class C subnet can accommodate 254 hosts at most. Similarly, you can study for yourself how many hosts can be accommodated in a Class A and Class B IP address segment. ..

After analysis, it can be concluded that the number of hosts that can be accommodated by Class B IP address is 2 16-2, and the number of hosts that can be accommodated by Class A address is 224-2. Based on the above, we can sum up a formula, the number of hosts = 2n-2, where the value of n is the number of hosts.