Summary Time The company needs to recruit a million oil-type computer personnel, the interview is n, not a few satisfied, almost everyone knows the IP division network. 192.168.1.5/20's IP segment start address and termination address, how many hosts have this section? ...... I will simply talk about this problem. In fact, this is a question about dividing the supernet / subnet. Many times we were confused by 192.168.x.x. If you want to be correctly divided, you must first forget the figures like 192.168, and from the nature of IP, we know that IPv4 consists of 4 8-bit binary numbers, a total of 32-bit, the expression is 11110011010101100 An IP address also requires a subnet mask. The IP address can be divided into two parts, part of the network segment number, part of the host number, the subnet mask is used to distinguish the network segment number. Usually IP network segments are classified into 5 classes: A, B, C, D, E. Commonly used is the 3 network segments of A, B, and C, how to assign you to see the relevant manuals, this is not much here. Let's take a brief analysis of the IP of 192.168.1/255.255.255.0. IP: 11000001.10101000001Submask: 1111111111111111111111111111111111111111. 00000000 This we can see that all parts of the subnet mask are 1 part is the network segment, and the latter identity is 0 is the host number, in this In the example, 1100000.10101000.00000001 is a network segment, and the last 00000001 is the host number. In the same network segment, the host number can be accessed with each other (IP address requires uniqueness). The number of hosts can be 8 times - 2, because the host number is 8 bits, so it is 8 times of 2, because the host number cannot be 0 or all 1, so it needs -2. I know how IP is divided into two parts, and we are easy to divide the supernet or subnet, for the above example (192.168.1.5/20):ip: 1100000.10101 (192.168.1.5) Submask: 1111111.111111111.111110000.00000000 (255.255.240.0) So very obvious this is a supernet, which borrows the last 4 digits of paragraph 3, then the number of hosts should be 2 squares. IP is its initial: 1100000.10101000.0000 0000.00000001 (192.168.0.0) 1111111.11111111.1111 0000.00000000 (255.255.240.0) is its termination IP: 1100000.10101000.0000 1111.11111111 (192.168.15.255) 1111111.11111111.1111 0000.00000000 (255.255.240.0) in Within this IP, you can ping each other, but for so many 1010 everyone is dizzy, we need to convert it into a decimal number, here give a simple method to calculate: for example 1 1 0 1 0 1 1 1128 64 32 16 8 4 2 Among these parts, you can get the corresponding numbers below, this 8 can you know that 128 64 16 4 2 1 = 215.
