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This **, directly under the IP network segment direct generator, fully meets your requirements.

It can also give you a paragraph**:

import ;

public class t

if((s1array[i-1]=>255) bb=false;Values greater than 255 are illegal.

Split S2StringTokenizer ST2 = new StringTokenizer(S2,".");

while(

j++;temp=;

if(>3 ||

bb=false;}

if((s2array[j-1]=>255) bb=false;

if(s1array[0]>s2array[0]) checks whether the start CIDR block is larger than the end CIDR block.

bb=false; else

if(s1array[0]==s2array[0])

if(s1array[1]>s2array[1])

bb=false; else

if(s1array[1]==s2array[1])

if(s1array[2]>s2array[2])

bb=false; else

if(s1array[2]==s2array[2])

if(s1array[3]>s2array[3]) bb=false;

if(!bb||i!=4||j!=4)

The entry is illegal");

else Valid input.

tmp[0] = s1array[0];

tmp[1] = s1array[1];

tmp[2] = s1array[2];

while(true)

ipseg="."+"."+".0";

if(tmp[0]==s2array[0])

if(tmp[1]==s2array[1])

if( tmp[2]==s2array[2]) break;

else tmp[2]++

else{tmp[2]++

if(tmp[2]==256)

tmp[2]=0;tmp[1]++

else{tmp[2]++

if(tmp[2]==256) {

tmp[2]=0; tmp[1]++

if(tmp[1]==256){

tmp[1]=0;tmp[0]++

public static void main(string args)

new t();

This becomes, called the network segment generator, and I am not afraid to try it myself.

4 departments, 62 machines in each department, just 2 places of class C. The first is, the address is, the mask, the second is, the address is, the mask, the third is, the address is, the mask, the fourth is, the address is, the mask.

Are you going to distribute this public network to about 250 computers?

1. The router comes with DHCP function (automatic allocation of intranet IP address);

2. The function of the router is to allocate 1 network cable that can access the Internet to N network cables that can access the Internet;

3. The external network IP is not the landlord's, it is the router's, and the landlord must also connect to the router to access the Internet, you are a level;

4. Your IP is an intranet IP, and it is impossible to be blocked, unless you are intentionally set from the router to not let you access the Internet. It can be understood that your IP block will not affect others to surf the Internet.

The DHCP function is turned on in the router, you don't need to manually set the IP address, your computer is set up to get it automatically, and after each startup, the router will automatically assign an IP address to you.

All of you have the same external IP address, and if you are blocked, of course everyone else is blocked.

However, if it is a virtual dial-up Internet access, you will get another public IP address if you restart the next route. Don't be afraid to block, unless you block the entire IP segment...

First of all, you don't need to set the IP, the landlord's router has DHCP function, which will automatically assign the IP, as long as the computer is connected to the router and automatically obtains the IP, then the router will automatically configure your IP, and secondly. The intranet IP and extranet IP you mentioned can generally be said in large companies or enterprises, for example, the internal charging network of a mobile company is called BOSS intranet. The external network is to access the Internet, the public IP is rented by the telecommunications company, there is no need for ordinary people to get it, the public IP is very expensive, so the private is generally useless, so what is the private IP?

Nowadays, most of the world's IP addresses use IPv4. But now IPv4 is gradually not enough, so what to do. Okay, then give the address you don't use to someone else first.

If you don't go online today, then I'll rent this address to others first, and when others don't use it, you don't use it, so I'll rent it to the person who wants to use it, so when you want to use the IP, there are always people who don't use it, so your landlord's IP is like this, it's a public IP, but it's not fixed, it's rented, and when you redial, it's another IP. Your IP actually makes the router do a net service. Map your LAN IP to the one rented by the landlord, so all of you are using the same IP address.

It is the public IP address rented by the landlord. The unified packaging conversion you are talking about, so to speak, but professionally it should be called mapping. If you still don't understand, then give me a message and explain.

Landlords generally don't set up if you choose to get an IP address automatically, and the router automatically assigns an IP address, generally starting at 100.

The so-called intranet IP is only for the IP router on the router segment to set the Internet access account password to access the Internet, then the IP segment of the LAN can be accessed.

This connection method is**wire divided into 2 1 follow-up** one to connect to the cat to the router router to multiple computers, your external network IP is the same.

If your IP is blocked, it's just that the IP on your router segment is blocked, and everyone else is affected.

First of all, you don't have to worry about why you can go online, you can go online, you really want to know, then I will simply say, your machine IP is automatically obtained, so the connection route will automatically assign you IP, you will join the LAN, the landlord's external network enters, then you can access the Internet three, do not need to manually IP so troublesome, (generally when you can't get the IP manual input).The Internet IP address you use is the same as the landlord's. Your network IP is blocked, is it only an intranet IP, if so, it is also blocked by the landlord, the external network you said, it is generally not blocked, blocked, everyone can't afford it,

1. If it is a problem with the broadband itself, first directly connect to the broadband network cable for testing, and if it is a broadband problem, contact the broadband customer service to solve it.

2. If it is a problem with the router, if it can be used originally, it cannot be used for the time being, my own practice is to disconnect the power supply of the router and plug it in, and I will see. In there is a factory reset, it can be used from the new settings (this is under the premise of the correct physical connection, when there is a fail-off, it is caused by the slow or failed IP address search of the router, not that the router is broken).

If it can't be solved all the time, it is recommended to call the customer service of the router, they have **** guidance, I encounter a problem that I can't solve by myself, it is very useful to consult the advice they gave, and they will give the correct advice for your settings or operations.

3. If you turn off the wireless switch, it is on and have a false reputation, if it is a wireless connection with software, it is normal for the software to be weak and often have problems, there is no better way, use a router. In addition, it is caused by the network card driver is not or is not suitable, and whether there is a problem with the network cable interface or network cable.

4. If it is caused by system problems, it is recommended to restore the system or reinstall it.

1.Class number 101 and student number 04, from which the IP address range can be determined. There are 16 people in the technical department, because the subnet needs to occupy 1 network address and 1 broadcast address, take the closest value, so it is 2 to the 5th power, that is, 27,.

There are 30 people in the sales department, and 32 IP addresses are required to go to the beginning and tail, which is 2 to the 5th power of 27. There are 8 people in the personnel department, and there are 10 people in the head and tail, so it is 2 to the 4th power 28. There are 4 people in the finance department, and the head and tail are 2 to the 3rd power 29.

2.Before planning, the default subnet mask was class); After the planning of the cherry blossoms, the technical department, the sales department, the personnel department, the finance department.

Pure hands to beat the blind macro, hope.

Hope it helps.

Don't worry, landlord, this question is not something you can figure out at once. I'm going to give you a brief overview of IPv4 as an example (many advanced applications can't be explained for a while).

First of all, it is necessary to understand the valid IP address (issued by the International Organization for Standardization, ISO) and the internal reserved address (; etc.); Effective IP address can be used directly on the network (universal use all over the world), the current effective IPv4 (fourth edition) address distribution is mainly controlled by the Yankees, the Asian region is managed by the University of Tokyo in Japan, we in China actually only get a few valid IP addresses, most of them are used internal reserved addresses, and then through a router (or other network interconnection equipment**), to put it bluntly, many people share an IP address, which also directly affects the quality of network communication in China.

The IP address (4th edition) has a total of 32 bits (binary bits): it consists of the network number and the host number, and the subnet mask is a subsidiary of the IP address, which uses the network number and the host number to distinguish the IP address. I'll give you an example of how you understand the relationship yourself:

For example, the IP address on a computer is:

Let's start by writing it as a binary number: 11000000 (binary of 192).10101000 (168 binary).

00000001 (1 binary).00010000 (binary number of 16) If it has a subnet mask of :binary:

Now pay attention!! Match the two.

ip: subnet mask:

In the network structure in which the computer is located, all the hosts representing the last decimal digit are all in the same LAN (ISO standard). The landlord understands carefully, and if you understand this, you will know the relationship between the IP address and the subnet mask.

DNS is a network application service, used to convert the network domain name into an IP address (equivalent to knowing your name to you to query your student number), in the actual network communication, the IP address shall prevail, so it needs to be converted, but the IP address is not convenient to remember, so the domain name (convenient memory) appeared, and the DNS server is dedicated to providing this service.

I am a computer network engineer, and if you don't understand the network, you can consult at any time.

Classification of IP addresses.

There are five categories of IP addresses, Class A reserved for ** institutions, Class B for medium-sized companies, Class C for anyone who needs them, Class D for multicast, Class E for experiments, and the number of addresses that can be accommodated varies by class. Characteristics of Class A, B, and C IP addresses: When writing IP addresses in binary form, the first digit of Class A addresses is always 0, the first two digits of Class B addresses are always 10, and the first three digits of Class C addresses are always 110.

1.Class A addresses.

IPv4 Class A addresses were designed to support giant networks, which were developed because there was little need for a huge network.

This structure results in a large number of host addresses and a strict limit on the number of networks that can be defined as Class A.

A Class A IP address uses only the first 8-bit group to represent the network address. The remaining 3 8-bit groups represent the host address.

Note: n is the network number bit, and h is the host number bit.

64 + 32 + 16 + 8 + 4 + 2 + 1. The leftmost bit represents 128, which is vacant here. As a result, there are only 127 possible Class A networks.

The 24 bits (3 dots, decimal number) after a Class A address indicate the possible host address, ranging from Class A network addresses.

Arrive. Note that only the first 8-bit represents the network address (n), and the remaining 3 8-bit groups are used to represent the table of the first 8-bit group.

Shows the unique host addresses in the network, which are 0 when used to describe the network.

Note that it is also a Class A address, but it has been reserved for closed-loop testing and cannot be assigned to a network.

Each Class A address can support 16777214 different host addresses, which is obtained by subtracting 2 from 2 to the 24th power. Minus 2 is necessary.

This is because IP keeps all 0's for the network and all 1s for the broadcast address in the network.

2.Class B addresses.

Class B addresses are designed to support medium to large networks. Class B network addresses range from to.

The outer two 8-bit groups represent the host number. The first two digits of the first 8-bit group of Class B addresses are always set to 10, and the remaining 6 bits can be both.

0 can also be 1, so that its range is less than or equal to 1 9 1, which is obtained by 128 + 32 + 16 + 8 + 4 + 2 + 1.

The last 16 bits (2 8-bit groups) identify possible host addresses. Each Class B address can support 64,534 unique primaries.

machine address, this number is obtained by subtracting 2 from 2 to the 16th power. There are only 16,382 Class B CIDR blocks.