Www.YUHUAN.COM Author: Yuhuan from: Yuhuan Website Click: 4 17 Time: 2005- 1-3.
What is an IP address "?" How to get your own IP address "?" How to get it?
Other people's IP address "? ..... Everyone has his own name, and so does the computer.
There is a host name locally. On the network, there is an IP address.
(1) "IP address":
"IP address" is "TCP/IP" (transmission e control protocol.
Transmission control protocol/Internet protocol).
The Internet can interconnect computers in a wide range of network systems.
Up, mainly because of the application of the "unified world" TCP/IP protocol.
In the network environment where TCP/IP protocol is applied, in order to uniquely determine the host's
Location, you must specify three parameters for TCP/IP protocol, namely IP address and subnet mask.
And gateway address. The IP address is actually based on the IP network layer through the upper software.
The method of "unifying" the physical address of the network uses a unified address.
Format, assigned to the host for unified management. On the internet, different
Hosts have different IP addresses. The IP address of each host is
It consists of 32 bits, that is, 4 bytes. In order to facilitate users' reading and understanding,
Usually expressed in dotted decimal notation, each byte is a part.
, separated by periods. Such as 61.129.64.150.
Is the IP address of the hacker power Web server. Each IP address can be divided into two parts.
. The network number indicates the size of the network, and the host number indicates the location of the host in the network.
Address number. According to the size of the network, IP addresses can be divided into a, b, c and d.
, e five categories, in which A, B and C are the three main address types, and D is dedicated to many kinds.
Multi-destination addresses are used for destination transmission, and Class E is used to extend alternate addresses. Category a, b and c
The valid range of IP address is as follows:
Category Network Number Host Number
a 1 ~ 126 0 ~ 255 0 ~ 255 1 ~ 254
b 128 ~ 19 1 0 ~ 255 0 ~ 255 1 ~ 254
c 192 ~ 223 0 ~ 255 0 ~ 255 1 ~ 254
In the IP address, several addresses have special meanings:
Broadcast address: According to TCP/IP protocol, all bits of the host number are IP of 1.
This address is used for broadcasting. The so-called broadcast address means that all hosts on the network exist at the same time.
Send a message, that is, regardless of the characteristics of the physical network, the Internet
The network supports broadcast transmission. For example, 136.78.255.255 is at address B.
A broadcast address, you send information to this address, that is, you send information to the network.
All hosts with network number 136.78. Limited broadcast address: sometimes it needs to be here
When broadcasting in the network, but I don't know the network number of this network, TCP/IP protocol stipulates.
32-bit IP addresses, all 1, are used for local broadcasting, that is, 255.255.255.
"0" address: TCP/IP protocol specifies the network number to interpret all zeros.
Into "this net." If the owner tries
Communication in this network, but do not know the network number of this network, then, you can use it.
"0" address. Loopback address The first decimal value of a Class A network address.
127 is a reserved address, such as127.1.1.13, which is used for network software testing.
And interprocess communication with that local machine. To quickly determine which part of an IP address
Network number, which part represents the host number, determines whether two IP addresses belong to the same one.
As soon as the network was established, the concept of subnet mask came into being. The subnet mask gives an integer.
The bit pattern of the IP address, where 1 represents the network part and 0 represents the IP host number.
Part, the application also uses dotted decimal representation. Use it to help determine IP addresses.
Where the network number ends and the host number begins. Standards for Class A, B and C networks
The default mask is as follows: Category Subnet Mask Bit Pattern Subnet Mask
a 1 1 1 1 1 1 1 1.0000000000.000000000 255 . 0 . 0 . 0
b 1 1 1 1 1 1 1. 1 1 1 1 1 1 1 1 1 1 1 1.000000.000
c 1 1 1 1 1 1 1. 1 1 1 1 1 1 1 1 1 1 1 1. 1.65438
55.255.0 If the IP addresses of two hosts communicating on the Internet are divided into two parts.
Don't be192.83.192.10 and 192.83. 192.32, then the subnet mask is 2.
55.255.255.0 and these two IP addresses.
After the operation, the network number and host number are obtained, and the results are consistent, so it can be judged that this
Two IP addresses belong to the same network. In ord to effectively solve that problem of network segmentation
Using IP address, you can grab the high-order part of the host number as the subnet number.
Extend the subnet mask from the usual eight-bit boundary to create a variation of a specific type of address.
Multiple subnets. But when more subnets are created, the available host addresses in each subnet.
The number will decrease. To determine the subnet mask of more subnets, the transport IP should be determined first.
The number of network segments of information flow, and then determine the minimum number of sub-network segments that can be accommodated.
The number of network masks, remember not to use all 0s or all 60s network address 1.
In order to connect two completely different networks (heterogeneous networks), we usually use.
Gateway, in the internet, two networks also have to go through a computer called gateway.
Realize interconnection. The computer can be determined according to the IP address of the user's communication target computer.
Decide whether to send the information sent by users to the local network, and also send the information to the outside world.
Receiving information sent to a computer belonging to a local network, which is a network and
A channel connected to another network. In order to make the TCP/IP protocol addressable, this channel
It has an IP address, called the gateway address.
Simply put, "IP address" is the "ID card" of each host!