Shulou(Shulou.com)06/01 Report--

Detailed explanation of the concept of ip

One: explanation of IP network segment

1:ip definition:

The IP address is the Internet protocol address and is the unique identification of the host. The IP address is used to specify the destination host address when communicating. There are two forms to represent the address of a computer in internet: one is a numeric address, called an IP address. The other is an address represented by letters, called a domain name address.

2: subnetting:

In order to improve the efficiency of the use of ip addresses, a network can be divided into subnets. By means of borrowing, the highest host bit is changed into a new subnet, and the remaining part is still the host bit. This makes the ip address structure divided into three parts: network bit, subnet bit and host bit.

| | xxxxxxxx.xxxxxxxx.xxxxxxxx. | xxxxxxxx |

Network bit host bit

Classification of 3:ip

classification

Class A 0mur127 08 bits 24 bits | xxxxxxxx. | xxxxxxxx.xxxxxxxx.xxxxxxxx

Class B 128Muth11919191 10 16-bit 16-bit | xxxxxxxx.xxxxxxxx. | xxxxxxxx.xxxxxxxx

Class C 192 Pure 223 110 24-bit 8-bit | xxxxxxxx.xxxxxxxx.xxxxxxxx. | xxxxxxxx

Class D 224Mutual 239 1110 Multicast address

Class E 240mur255 1111 retention test use

Special address:

Network address: the host address is all 0, that is, 172.25.254.0

Direct broadcast address: the host bit is all 1, that is, the broadcast address with host bit 172.25.254.124 is 172.25.254.255, which means that messages can be sent to all hosts in the same subnet at the same time.

Limited broadcast address: a 32-bit full "1" IP address (255.255.255.255) is called a limited broadcast address, which is usually used by a diskless workstation when booting. You want to obtain an IP address from the network IP address server.

The host itself address: (0.0.0.0) is called the host itself address.

The loopback address: 127.0.0.1 is called the loopback address, which is often used for the communication address between the local software test and the network application on the local machine. No matter what program, once the data is sent using the loopback address, the protocol software immediately returns it without any network transmission. Packets with network number 127 cannot appear on any network

Private IP address range:

You can use it when setting up your own network.

ARV 10.0.0.0mm 10.255.255.255

BRV 172.16.0.0mm 172.31.255.255

192.168.0.05192.168.255.255

Two: subnet mask

With the introduction of the concept of subnet, network bits plus subnet bits can uniquely identify a network globally. All network bits are identified by 1 and host bits are identified by 0, and the subnet mask is obtained.

The ip bits corresponding to the subnet mask 255bits are network bits.

Ip bit host bit corresponding to subnet mask 0

32-bit IP addresses are divided into four groups of 8 bits each. If the four bytes are represented by wre _ x _ x _ y _ z respectively, the range of these five types of addresses is:

Category A: IP:1.x.y.z-126.x.y.z 255.0.0.0amp 1111111.00000000.00000000.00000000

(among them, 127.0.0.1 is not used as an IP address and is used for internal network use)

Class B: 128.x.y.z-191.x.y.z 255.255.0.0Category 16

Class C: 192.x.y.z-223.x.y.z 255.255.255.0

Class D: 224.x.y.z-239.255.255.255 (where 244.0.0.0 is not used, 224.0.0.1 is assigned to permanent IP host groups, including gateways)

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.