ip的划分,超详细.[经典]（The division of IP, with super classic].）.docVIP

ip的划分,超详细.[经典]（The division of IP, with super classic].） The division of IP, with super classic]. IP and subnet mask As we all know, IP is composed by four figures here, we first look at the 3 kinds of commonly used IP A class of IP 0.0.0.0 to 127.255.255.255 B IP 128.0.0.0 to 191.255.255.255 C IP 192.0.0.0 to 223.255.255.255 XP subnet mask default allocation each only 255 or 0 The default subnet mask 255.0.0.0 a subnet of a computer can accommodate up to more than 16 million 770 thousand The default subnet mask 255.255.0.0 a subnet of the B class can accommodate up to 60 thousand computer The default subnet mask 255.255.255.0 a subnet of the C class can accommodate up to 254 computer I used to think, want to engage in some computer on the same network, as long as the IP in the first three paragraphs as you can, today, I know I was wrong. If I say, a subnet can only accommodate 254 computer? Is really a little joke. Look at it with us. To be in the same segment, as long as the same network logo on it, to see how the network identification? The first thing to do is to convert each IP into binary. (some people say that I cant convert yeah, never mind, we use the Windows built-in calculator on the line. Open the calculator, point of view scientific type, input a decimal number, and then click the binary this radio, you can switch to binary). Handle network switching to binary, we will find that all the subnet mask is composed of 0 by a string of [red] continuous [/red] 1 and a string of [red] [/red]s (a total of 4 sections, each section 8, a total of 32 digits). 255.0.0.00000000000000000 255.255.0.01111111100000000 255.255.255.01111111100000000 This is the A/B/C three default subnet mask in binary form, in fact, there are a lot of subnet mask, as long as it is a series of 1 and a series of 0 can be (each 8). Such as1111111100000000, which is a valid subnet mask. Subnet mask is a number of