How powerful is that how the global network of the Internet works. We create a simple local network as a working Internet provider

Golovna / Usunennya malfunctions

On this day, the Internet has become one of the most important warehouse life of people. Obviously, the wine is not important, like water or a product of eating, but this day has led to an informational collapse on the entire planet and, in fact, has shown humanity a hundred years ago. Let's take a look at what the Internet is like and why wine is so important to our life.

The Internet is a combination of all small links in a single global link with special cables. Explanation of the terminology is fully understood, but it does not explain much to the transverse coristuvachev, through which it is necessary to bring the butt open.

Give it up:

On the back of the island, chi continent, de povnіstyu bіdnі dvіdnі vіlyakі mérіzhі, аlе аlѕо саn аnd counting cars.
The skin computer had a lot of files, like multimedia, and important information.
In order to transfer the file to another correspondent, it was necessary to take digital information (a disk or a floppy disk), write down the data and especially show it to the person who needed the stink.

It was more possible on the territory of the place, as a maximum, the edge. Such a method is very unhandy and impractical.

After a certain hour, people began to connect the nearest computers with special cables - to create local networks. Nothing else could be called the Internet, but it became the cob of a global network. Vseredinі local z'єdnannya it is possible to transfer any kind of information. Over the years, more and more computers were brought together, until all the counting machines within the borders of one island, the edges or the continent did not create one great net.

Tsyyu mezhezh already can be called the Internet, but the all-world web is more global. The principle of її pobudovi similar to local ї merezhі, only computers on different continents are connected. with different cables, like they are laid by the bottom of the seas or oceans. If the main cables that run, will be like a rank of zruynovan, then they will be changed again on a large-scale, but localized. How to use the Internet through digital networks: all the files that are transferred are divided into packages and managed on a security basis, assuming your provider's tariff plan.

Vineyard of the Internet is not one person, but a whole group of Americans. The reason was the Cold War in the Soviet Socialist Republic and the measures of guilt were like a rank to counter the threat. The project was expanded on the basis of a new age of 1969, but a wide expansion of the Internet began only in 1991.

The essence of the work of Internet providers

Irrespective of the frequent interactions with such corporations as Rostelecom, Beeline, MTS and others, a lot of people do not know who such an Internet provider is. Under this term, there is no one else, like a postal worker of the servants of telecommunications, including the Internet.

Internet Service Provider - an Internet service provider, that is a company that encourages customers to connect to a virtual network for a small fee. The firm itself will have access to the global darkness, which is what it promises to its own employees.

So that the client of the postal worker of the service is instantly connected to the Internet at home, he can have connections to one of the provider's servers. Servers are also connected to booths and private computers for the help of long-term cables. However, there are fewer providers, fewer people, who provide access to the global network, which significantly affects the security of the business. The server itself can achieve a large throughput capacity, but if it is distributed on all clients, only a small part of them is available to the skin.

For a more accurate assignment to whom and how much of a part of it the providers guessed understand the "tariff plan". The maximum cost is easily calculated by the maximum speed of access, as well as the visibility of the border in terms of traffic that is downloaded. The most advanced tariffs offer speeds from 100 to 1000 Mb/s, however, they cost more expensive, lower rows of 30-80 Mb/s.

For the identification of a correspondent, a special address - IP - is selected for the common Internet. In order to correctly identify you as a provider, you need to enter a login and password when connected. For the help of these dans, you can also visit the internal special office on the website of the post-master of the servants and cherubate the servants. You and I have figured out who are the Internet providers and what is the essence of their reasoning, and also how ugliness can be taken away from the skin in connection with these companies. But the stars themselves can be taken by the post-employees by access to the virtual light barrier and how can they transmit the signal to the local computer?

How do ISPs work?

We already know that all the computers of the world are among themselves, then why not show themselves to the servants of the merezh without intermediary? The process of transferring data is not as easy as it seems when you first read the word "Internet". Merezha to avenge even more information and її it is necessary to save here. Even small websites can be hosted on local computing machines, such as Wikipedia, Google, AliExpress and other large-scale websites run on super-large PCs with a large number of hard disks. The access architecture is as follows:

From servers to conduct video surveillance of high-speed highways.
Gateways of Internet providers are connected to the highways.
Gateways to local networks or private PCs are maintained from the post-manager.

Tsya scheme is very simple, but it is fully accessible to the skin. Dalі varto explain, like the same rank of PC coristuvacha vzaєmodіє z Іnternet.

After connection to the postal company, your apartment will have a coaxial or fiber optic cable, which is connected to the router or directly to the PC. In this rank, you can connect to the provider's server.
For further work, you need to install a special web browser and browser. The most popular today are: Google, Yandex, Firefox. For the help of these programs, you will be able to review videos, read books, and look at new things.
When a specific request is entered, the browser's search row, the program sends a signal to the provider's server. Stay, at your desk, transfer it to all available world servers to search for relevant information to the client.
After picking up the data, the signal is turned to the provider's server and retransmitted to the client, and now the browser does not show an empty field, but all the data you need.

Trapplyaєtsya so that the koristuvach can't take advice on a specific request. It depends on a number of reasons: inaccessible server, on which information is stored, inaccessible specific file with data or content that is requested, blocking in your region by Roskomnaglyad. Do you have any kind of attitude, you take away all the necessary information.

Where does the Internet take care of, so how do we take access to sites?

The All-World Merezha is a collection of all the knowledge of rich generations. Nothing can stop the importance of this information, even if new sites are created and the weeks are seen, but the Internet is saved, how great is the fault of the flooring? How can a supercomputer be created that can accommodate such a great data base?

The answer to food is even simpler: if you use the Internet to buy all the PCs in the world, then you can save wine on them, even in small parts. As a retailer, I create a special site, the code is stored on the computer, and the short-term credits can be looked over for access to the Internet. The same applies to photographs or other multimedia files. And yet, there are data bases that are impossible to leave in a PC: great web resources, social media, online stores and other portals are hosted on great servers. Well, big data bases are stored in data centers, which can be mentally called “dumbass” of data.

Before the speech: the first Internet was the Arpanet network, and the first reminder, as if it was far away to transfer for help, the word “login” was called. Vono was violating by student Charlie Kline, but at the end of the hour of transmission, becoming zbіy і to the end of the coristuvach, there were only the first two letters - “lo”.

Let's turn back to the power to save the files to the Internet and take a look The most popular data center in the whole world.

Digital Beijing. Raztashovaniya in Beijing and zvedeniya in honor of the Olympics 2008 rock. A special feature of the center is the use of light-emitting lamps, which gives the ability to speed up the use of electricity by 60%. The walls of the majestic life of vikonanі zі skla, the stench is necessary for the protection of the internal accommodation from the sony heat, which is dodatkovo quickly vitrati on the cooling of the servers.
Apple. Roztashovuetsya at Pivnichniy Carolina, USA. The company is famous for the fact that the river has a short supply of sizable electricity. For the firmness of її directors, practically all the vibrations of that office work in the form of energy, which is vibrated by sony batteries. And it's not surprising - the center of ablutions is 400 thousand sq.m.
city group. Raztashovaniya at Nіmechchinі and vvazhaєtsya environmentally friendly, as well as green data center. The servers of that victoria are not to be run over by any nasty little middle ground, which was designated by all governmental organizations.
Telehouse West. Raztoshovaniy in London, vіdrіznyаєє vykoristannym data centers for rent to great companies. Due to the fact that it is technically impossible to place sony batteries or even more so in 2011, the company began to purchase energy from other manufacturers.
telefonica. The Spanish center borrows a lot of football fields and secures the savings of the data of local coristuvachs, as well as clients from Germany and England. Part of the resources is given to hiring companies. The center is the third in the world behind the roses, rewards as the most important.
EBay. USA. The main feature is the expansion in the Arizona desert, where the temperature is significantly higher, lower for the data center to function. Average temperatures reach +46 degrees, water circuits are used for cooling vicor, all servers are placed in containers, which redirect energy not to lower temperatures, but to work efficiency.
Google. Roztashovani in the whole world, more centers in compliance with "green standards". Tі, scho roztashovanі on the shores of the seas, for example, the data center near Finland, vikorivuyut for cooling servers only krizhanu or cold water, which will soon be drained.
Verne Global. Iceland. The data center is won by the BMW concern. Earlier, having changed wines at Nimechchyna, and after the transfer of servers to the territory of a larger brewing country, a 100% decline in charcoal was noted, which is important for dovkil. For the generation of energy, there are vicarious geysers here, which is why nature is at a minimum.
IBM. Created in 2009 roci in the USA by experimental way. The company was lucky enough to see pennies for everyday life only in that moment, as if a method would be found that allows you to reduce your spending on electricity. As a result, the data center takes energy from gas turbines, the efficiency of which is 60% higher, lower for ordinary ones.
Hewlett Packard. Pivnichna Great Britain. Do not lie down to environmentally friendly enterprises, but obviously it’s not the right thing to do. Winds on the air-conditioning are quick to see the airs of the air vents: two fans can trim the temperature that is optimal for the server without the need for electricity to the outside. Roztashovane entrusted the sea with the possibility of installing wind generators, as well as generating energy.

There are only 10 main data centers, but they are scattered around the world even more and the stench will continue to be greater than the amount of information in the region. The area of \u200b\u200bprimіschen that sumi vitrat on their everyday life is practically neimovіrnі, and how much money they save on them is scary to reveal.

How can I help the domain to know the required site?

There are billions of sides and sites on the Internet, there are more richly, less people on the planet. If there is a census for people, where namesakes are often mentioned, namesakes, or hulks have started with identical PIBs, then this is unacceptable. What is the domain name: the number of symbols in Cyrillic or Latin, speckled divisions into two or three parts.

Varto to set the example for a complete understanding of nutrition: renaming the site mysite.com is the same as the domain name. It is separated by two dots, and is also composed of three different domains:

Domain of another equal- My site. Vin sets the name of the site itself. Which is shorter, which is more beautiful, and then follow the main idea and theme of the resource.
Upper level domain- Com. Indicates the directness of the portal, for example COM - means commercial, also on this site it is sold, the creations for collecting pennies are too small, RU - the national Russian domain zone. Їx already rich.

The rest of the hour for the registration of new sites in vistachaya be-yakah two of the other structures. Do not forget that before creating the site it is necessary to check the domain names - two of them are not guilty.

How does the Internet work?

The Internet is an international system of computer networks based on IP and routing of IP packets. For a foldable, even folded-out system, the Internet allows you to store millions of computers in the whole world. We encourage you to recognize how the Internet works.

Structure of the Internet

In the whole world, in the offices of companies, state institutions, at private booths and apartments, there are computers. Okremimi groups of stench are united at small local networks (from computers to organization to the city). You join with your own chergoy at the great borders - regional, national. The stench is also a part, but even more large-scale merezh - continental. Tsі merezhі are interconnected by colossal for the parameters of the undersea transatlantic fiber optic cable. For a piece of clothing, for example, a computer, which is worth in Orly, ties with a computer near Vancouver. Koristuvachi tsikh two PCs via the Internet can communicate one with one.

Moreover, as the Internet is practiced on the international, world-wide level, it can be reached for the account of the global border - the totality of all computers in the world, from among themselves for the help of the Internet. Rozmіri її truly colossal, even if it’s practically stalking the entire planet for a little bit of rare little flowers, yakі through geographic, social, political and other reasons do not think it’s possible to use a similar resource.

In addition, it is necessary to complete the great lines, which are not connected, but only often made at once with other lines of the light Internet. For example, this is the situation in Pivnichny Korea. In this country, access to the “All-World Pavutin” is granted only with the permission of the authorities, and officials of the highest rank may have the right to a new one. In the middle of the very edge of the country, the internal network under the name “Kwanmen” became available to the local community not long ago. The quantity of information and its nature are strictly controlled by the government of the republic.

How to work with the Internet: warehouse elements

Whether it’s a link to the Internet (if we are looking for information, it’s possible to see the site and that in.) - folded lancets of the last ones that are found in the border. Moreover, the skin is such a process of transferring the appearance of clothes to warehouses. Let's briefly chime in on them.

Koristuvach

Otherwise, as an automatic program, it forces you to ask on the Internet to retrieve information.

Computer

Or be it some other way to access the Internet, for example, a phone, a tablet. Without such outbuildings, it is impossible to enter the border.

Internet provider

This is a commercial organization, a company that provides access to the Internet for 8 computers. The skin area has its own providers. With this, all providers of the world are divided into 3 great categories.

First - tse rulers as a part of the light Internet, as they can sound their fiber optic networks, as stinks and transmit traffic (so that tasks can be shared with information, as they can be taken via the Internet) to the network providers of the lower group.
Another - all companies of national and regional equals (created by a large number of suddnim krajany). For example, tse Rostelecom.
The third one is all other participants of the market, represented by smaller firms-providers in localities and regions.

Finances mutually, which signify, zocrema, the amount of traffic taken off between the two groups (and especially between the first and the other category) providers are more collaborative. Here, the role of economic moments often plays a role, as well as special interests, politics and others.

Browser

This is a client program for working on the Internet, which can be installed either from a disk or via the Internet. The most popular browsers are Google Chrome, Internet Explorer, Mozilla Firefox, Safari, Opera.

Koristuvach can be installed on your PC absolutely no matter what browser, or you can download some programs for your needs. The skin program has its own characteristics, pluses and minuses.

Domain

Let's understand it, it's on the wrong side, as if the zone on the Internet is occupied by another site. Obviously, the skin page on the Internet can have its own unique domain name - the address, for which you can know the site of the merezhі.

Having launched the browser, in the address bar you enter the domain name of the resource you need. After that, the system is sent from the power supply to the Internet provider. The provider is a server of the DNS (Domain Name System) type, which allows you to recode the domain name of the site into an IP address. IP-addresses (Internet Protocol Address) - the same unique address as a zone on the Internet, presented, on the surface as a domain name, in the form of numbers. Before speech, IP-addresses can be not only websites, but computers themselves. The IP address is given to the skin PC by the Internet provider, which gives access to the device. It is necessary to fight in order to be able to send traffic to the required address, so that it reaches the skin specific PC, and also to eliminate problems in the service.

After the IP-address of the site is recoded from the tenth system to the number two (for participation 0 and 1). In this way, the provider, through the server, sends a request about the removal of information from the required koristuvach to the site on the router.

router

Insha I’ll call this attachment - a router. It will ensure the transfer of information through the mesh. It can be said that the router is the cousin of the GPS-navigator, which wins in life. Knowing the distribution of two points (there is a computer on the Internet and a website on the Internet), the router lays the necessary paths between them to ensure the exchange of information.

The transfer of information is carried out from one router to the other to the end point - the server.

Server

An exhausting computer, which can be hacked in the fall in the first sight of such a task:

Take care of the management of Internet traffic by computers.
Engaged in recoding domain names to IP addresses.
Save data. For example, you can have a server with data of correspondence such as electronic mail: incoming and outgoing sheets, sheets in the box and folders with spam, information from address books and in.
Retrieve from your memory information about the different sites of the city, all the data on them. Such servers are called hosting.

Obviously, in our application, there will be transfers through routers to the external hosting, which collects information about the search engine's Internet site. The server response will be sent via the gateway (through routers, Internet providers and browser) to the PC.

However, the first result will be displayed on the monitor, for the transmission of information, one of the numerical ports, like a victorious PC, will be used.

Port

This is a system resource, which is seen as an add-on for communication with other software programs. So, depending on the same IP-address, these other data will then be separated by different ports. So, the main port for the administration of electronic mail and the okremo - for the її otrimanna.

For work with websites, use an okremy port. Vіn analyze otrimana іnformatsiyu and vіdpravlyaє її to the browser. At the result, we see a bad side.

In fact, the entire description of the process takes a few more than a few seconds. You can judge for yourself by trying the site. The page will appear before you literally in a minute after you enter your domain name in the address bar, or, for example, enter the request at the browser prompt.

In this article, I will tell you how to create a simple local network between two computers connected for an additional switch / router.

How to create a local mesh

We need to give all computers original names and include them to one working group. For this on the skin computer, right-click on "my computer", open the "authority" tab "My computer", press the "change" button.
At the vіknі we introduce the original name of the computer (without spaces, in Latin letters), as a working group we will name the name “HOME”. Pressing "ok" and restarting the computer. If there is a router in the measure, then the Raja should be able to victorate paragraphs 7 and 8, if not, you can’t just double-check the folder with paragraphs 3,4,5,6.
Now we have a curved connection:
For Windows XP: Menu "Start" - Panel keruvannya - Merezha and connection to the Internet - Merezhevі connection.
Windows 7: Start menu - Care panel - Revision will become a task - Editing adapter parameters.
At the border connections, you will click "Connection by local border", click on the new right button and show the power. In the tab "Zagalne" (Windows XP) or "Merezha" (Windows 7), you can see "Internet Protocol (TCP\IP)" (Windows XP) or "Internet Protocol Version 4 (TCP\IPv4)" (Windows 7) and "power" button
It is important, since you already have the addresses registered, you need to copy them on papier, if pardons appear and you can be reminded. At the same time, the radios are switched to the position “Check the next IP address:” and “Check the next DNS server addresses:”
Now we enter our data:
If there is a router in the network, then the first 3 groups of IP addresses are changed for all data. In our case, the router with the IP address 192.168.1.1 is victorious, and only the number in the remaining group is changed in the connection with the cim for the IP address, the first 3 groups of numbers are left out 192.168.1.2.
IP addresses: 192.168.1.2
Subdivision mask: 255.255.255.0 (Same on all computers).
Default gateway: 192.168.1.1 (router IP address)
Love DNS server: 192.168.1.1 (IP addresses of the router)
Alternate DNS Server: 8.8.8.8
Pressing "OK" and curving the power of the connection to the local border.
Now you need to create a split folder on both computers (or open access to the explicit folder), for which you right-click on the folder you need, and it will open the power, open the "Access" tab. If you want to work ahead - click on the inscription "If you understand the potential of the problem, but all the same you want to turn on the sleep access without the help of the master, click here."
For the merger, select "Just increase shared access to files"
Now, in the “Access” tab, check the boxes “Allow access to this folder” and “Allow files to be changed through the link”. We press "ok".
Reboot the computer, open the connection and everything went right - I'll save the folder of the other computer.

TCP / IP protocol or how the Internet works for dummies:
At the heart of the work of the global Internet is a set (stack) of protocols TCP / IP - a simple set of good rules for exchanging information.
Have you ever experienced panic and total bezporadnist accountant when changing the version of office software - with the smallest change in the sequence of clicks of the bear, necessary for vikonnannya zvichnyh diy? Have you ever had a bachiti person who falls into a stupor when changing the work table? Axis in order not to be a sucker, it is necessary to understand the essence. The basics of information give you the opportunity to feel confidently and freely - quickly solve problems, correctly formulate nutrition and normally communicate with technical support.

Principles of operation of the Internet protocols TCP/IP for her day, she forgives the work of the radian post:
You write a sheet on the back, then put it in an envelope, seal it, write the addresses of the official of that officer on the back of the envelope, and then bring it to the nearest postal address. They gave the sheet to pass through the mailbox of the post office to the nearest postal office of the holder, the stars are delivered with a titko-license to the specified address of the holder and go down to the postal screen (with the number of the first apartment) or are handed out separately. If the holder of the sheet wants to tell you, then you remember the addresses of the holder and the official, and the sheet is forwarded to you by the same lancet, but at the return direct.

Headmaster addresses:
Type of person: Ivanov Ivan Ivanovich
Calls: Ivantivka, vul. Velika, bud. 8, apt. 25
Oberzhuvach addresses:
To: Petrov Petro Petrovich
Kudi: Moscow, Usachevsky Provulok, 105, apt. 110

Let's take a look at the interplay of computers and add-ons for the Internet, and for the local networks. The analogy from the great post will be better again.
A leather computer (vin: vuzol, host) at the borders of the Internet may have a unique address, as it is called IP (Internet Pointer), for example: 195.34.32.116. IP addresses are composed of four tens numbers (from 0 to 255), separated by a dot. But knowing the IP address of the computer is still not enough, because It is allowed to exchange information not by computers by powerful forces, but by reports, as they work with them. And on the computer, you can immediately run a copy of the program (for example, a mail server, a web server, too). To deliver a great paper sheet, it is not enough to know the address of the house - it is also necessary to know the number of the apartment. Also, the skin of the program addendum may have a similar number, naming the port number. More server add-ons may have standard numbers, for example: mail service binds to port number 25 (it seems: "listen" to the port, receive notifications), web service binds to port 80, FTP - to port 21 just. In this rank, I can come up with a practical analogy with our usual postal address: "house address" \u003d "computer IP", and "apartment number" \u003d "port number"

Source address:
IP: 82.146.49.55
Port: 2049
Destination address:
IP: 195.34.32.116
Port: 53
Given to the package:
...
Obviously, the packages also have service information, but for understanding the essence, it is not important.

The combination "IP address and port number" is called "socket".
For applications on socket 82.146.49.55:2049, we send a packet to socket 195.34.32.116:53, then. the packet is sent to the computer that has an IP address of 195.34.32.116, port 53. And on port 53, a name recognition server (DNS server) is sent, which accepts the packet. Knowing the address of the source, the server can, after processing our request, form a packet to the source, which will direct the gate to the socket of the source 82.146.49.55:2049, which for the DNS server will be the master socket.

As a rule, the interaction is based on the “client-server” scheme: the “client” requests any information (for example, the side of the site), the server receives the request, processes it and sends the result. The port numbers of the server programs are important, for example: the mail SMTP server "listens" on the 25th port, the POP3 server that ensures the reading of mail from your mail screens "listens" on port 110, the web server - the 80th port and in. Home computer with clients - for example, Outlook mail client, web browsers IE, FireFox and others. Port numbers on the client are not fixed like they are on the server, but are dynamically assigned by the operating system. Fixing server port numbers may start up to 1024 (alternatively, blame), and clients start after 1024.

IP is the address of the computer (node, host) in the merezhі, and the port is the number of the specific program that works on this computer. However, it is important for people to remember digital IP addresses - where better to practice with literal names. It's easier to memorize a word, but it's easier to remember a word, an_zh dialing numbers. So it's broken - whether a digital IP address can be matched with alphanumeric names. As a result, for example, Deputy 82.146.49.55 can win the name of www.ofnet.ru. And the transformation of a domain name to a digital IP address is handled by the service of domain names - DNS (Domain Name System).

We type in the address bar of the browser the domain name www.yandex.ru and tisnemo. The following operating system works like this:
- Enforce the request (more precisely, the packet from the request) to the DNS server on the socket 195.34.32.116:53.
Port 53 is sent to the DNS server - an addendum that deals with recognizing names. And the DNS server, having processed our request, turns to the IP address, so it confirms the entered name. Advance dialog: What is the IP address for the name www.yandex.ru? Certification: 82.146.49.55.
- Let our computer install a connection with port 80 of the computer 82.146.49.55 and power up the request (package from the request) on the otrimannya page of www.yandex.ru. The 80th port is sent to the web server. In the address bar of the browser, port 80 is not written, because. vikoristovuєtsya for umovchannyam, but yogo can and clearly show after two-fold - http://www.yandex.ru:80.
- Having accepted the request, the web server processes it and sends us a side in a new HTML in decal packets - a new text layout, a smart browser. Our browser, otrimavshi side, displays її. As a result, we see the main page of this site on the screen.

How should I know?
For example, you commemorated the wondrous behavior of your computer - unrecognized merezheva activity, galma and іn. What work? Open the console (press the "Start" button - "Vikonati" - type cmd - "OK"). At the console, we type the command netstat -an і tisnemo. This utility displays a list of installed connections between computer sockets and remote node sockets.
How can we see in the column “Own addresses” there are other people's IP addresses, and through the port 25 port, what can it mean? (Remember, does port 25 go to the mail server?) This means that your computer is connected to the mail server(s) and works through the new mail server(s). If your mail client (Outlook, for example) hasn’t launched for an hour, and if there are more such calls to the 25th port, then, obviously, your computer has a virus that spreads spam in your name or forwards numbers your credit cards at once with the passwords of the attackers.
Also, the understanding of the principles of the work of the Internet is necessary for the correct configuration of the firewall (firewall) - the program (often supplied together with an antivirus) is recognized for filtering packets of "own" and "prophet". For example, your firewall tells you if you want to install a port on your computer. Permit me to fence?

All this knowledge is too dark pіd h s pіlkuvannya z tekhpіdtrimkoyu - list of ports, with which you happen to get stuck:
135-139 - qi porti vikoristovuyut Windows for access to the hard resources of the computer - folders, printers. Don't call out the port and name, that's it. to the regional local area and the Internet. Їх лід close the firewall. Also, if you don’t check anything in the local fence, otherwise you don’t check, then it’s due to the fact that the firewall blocked the ports. In this way, for the local area, the port is guilty, but it is closed, and for the Internet it is closed.
21 - FTP server port.
25 - Port of the mail SMTP server. Through this, your mail client overpowers the sheets. The IP address of the SMTP server for that port (25-a) should be specified in the settings of your mail client.
110 - POP3 server port. Through this, your mail client collects the sheets from your mail screen. The IP address of the POP3 server on that port (110th) should also be specified in the settings of your mail client.
80 - WEB server port.
3128, 8080 - proxy servers (configured in browser settings).

Dekіlka special IP address:
127.0.0.1 - tse localhost, addresses of the local system, tobto. the local address of your computer.
0.0.0.0 - so all IP-addresses are assigned.
192.168.xxx.xxx- addresses that can be fairly tagged in local networks, but not tagged in global Internet networks. The stench is unique only at the borders of local borders. Addresses from this range can be selected for your own reasoning, for example, for home or office purposes.

What is the mask of the underworld and the gateway for the locks, is the same router and router? The digital parameters are set in the connection settings to the measure. Computers are connected to a local network. At the local network of computers, there is more than one in the middle. Local networks connect with each other through gateways (routers, routers). The pdmerezhi mask is recognized for appointment - chi lie down the computer-observer to the tsієї local ї mirezhі chi nі. If the computer-operator lies on the fence, like the computer-controller, then the packet is transferred to you without intermediary, otherwise the packet is sent to the gateway for locking, which is far away, for the routes that you know, transfers the packet to another network, tobto. to another postal order (by analogy with paper mail). Father:
TCP/IP- tse naming a set of merging protocols. In fact, the package that is being transmitted must pass through the bank of rivers. (As in the mail: write the sheet on the back, then put it in an envelope with the address, then put a stamp on it, etc.).
IP protocol- Tse protocol of the so-called lace line. The manager of this level is the delivery of ip-packets from the controller's computer to the manager's computer. Krіm vlasne danikh, packets of the same equal can be sent to the ip-address of the manager and the ip-address of the owner. The port numbers on the Merezhnoe River are not vikoristovuyutsya. To which port = addendum this package was addressed, but which package of deliveries was spent, to which it is unknown - the same order, the order of the transport line.
TCP and UDP- Tse protocols of the so-called transport level. The transport rіven is located above the railing. On this level, the port of the owner and the port of the owner are added to the package.
TCP- tse protocol іz vstanovlennyam z'єdnannya and z guaranteed delivery of packages. The exchange is often carried out with special packages for the installation of a contract, it is necessary to get a handshake (-Hello. -Hello. -Hello? -Come on.). Then, according to the order, they sent the packets back (Ide Rozmov), moreover, with a reverberation, the packet was delivered to the order. If the package is not sent, the wine is asked again (“repeat without feeling”).
UDP- all the protocol without the introduction of a contract and with non-guaranteed delivery of packages. (Type: shouting shchos, but to feel you chi ni is unimportant).
Above the transport level there is an applied level. On the other hand, such protocols are used, such as http, ftp and int. For example HTTP and FTP- Victory over TCP protocol, and the DNS server works through the wrong UDP protocol.

How to look over current orders?- For the help of the netstat -an command (parameter n specifies IP addresses and replacement domain names). The command is launched like this: “Start” - “Vikonati” - we type cmd - “OK”. At the console (black) that appeared, we type the command netstat -an and tisnemo. The result will be a list of connections installed between the sockets of our computer and other nodes. For example, we take:

For this example, 0.0.0.0:135 means that our computer is listening on all its IP addresses (LISTENING) on the 135th port and is ready to accept on a new connection from anyone (0.0.0.0:0) over the TCP protocol .
91.76.65.216:139 - our computer is listening on port 139 on its IP address 91.76.65.216.
The third row means that it was installed at once (ESTABLISHED) between our car (91.76.65.216:1719) and that far away (212.58.226.20:80). Port 80 means that our machine has returned from the request to the web server (I have a clear window in the browser).