Check network connections. How to check the network connection. We restore the operation of the cable network

At first glance, it may seem that the computer, being connected to global NetworkIt uses only a few connections, but in fact there are tens of such connections.

If you want to make sure that yourself, use the special TCPVIEW utility designed to track all the connections existing in the system (monitoring of connections) using TCP and UDP protocols.

TCPView utility belongs to the authors of the famous specialist in windows security Mark Russinovich and is part of the SysInternals Suite package. It is free, despite the English-speaking interface is very easy to use and does not require installation.

When you start TCPVIEW, it monitors connections and displays a list of all processes using TCP and UDP connections.

At the same time, the main parameters of each connection are displayed: the process name, protocol, identifier, connection status, remote and local addresses.

TCP and UDP protocols are the rules on which data is exchanged within the network. For example, TCP protocol is very similar to the work of ordinary mail.

Delivery of letters from the sender to the recipient and, on the contrary it is possible only if the correct address is affixed on the envelope.

The same thing happens when transmitting data on the TCP protocol. Any program that uses the Internet has a special identifier and is called the port number.

Many programs have standard numbers, such as data transmission applications on FTP have number 21, who had to work with immediately understand what we were talking about.

Monitoring of connections

So, thanks to the TCPView utility, you can find out what application uses an Internet connection, who is connected to you and which ports are listening.

This will fully control the network activity of any program, including malicious, because, especially trojans, very often use a data transmission connection.

Having found a suspicious connection, you can close it or completely complete the process.

With the current connection to the network, it can be noted that some rows of the endpoints of the connection are constantly changing the color, exactly the traffic light. This is done specifically that the user is more convenient to track changes.

So green It will not be observed that the points that are yellow - those whose status suddenly has changed, and the closed points of the connection will be redightened.

All information is updated every second, which is, according to the developer, the most optimal to monitor connections, but you can change the update speed or even disable it by selecting in the menu VIEW. paragraph Update Speed..

By default, the data on the IP address and the port number is displayed by the letter characters.

If this seems uncomfortable to you, press Ctrl + R and the utility immediately switches to the digital display mode. To view the full path to the process file, you must double-click on the selected row.

In the properties window that opens, you can view the full path, the version of the executable file and, if necessary, complete the process by clicking on the button " End Prose".

This operation, data copying ( Copy), as well as completing the connection without removing the process ( Close Connection.) You can perform from the context menu TCPVIEW called as usual right key Mice. Download the program S. official Site

To manage the main network equipment, be it Ethernet, Bluetooth, Wi-Fi, mobile Internet or connecting other types, you can also use the "Network" - "Network Management Center and common access ". Access to it you can get in two ways: scoring the name in the search field of the miracle buttons or by right-clicking on the network icon on the desktop.

To view, installed on your computer, network hardware, click on the left pane on the "Changing Adapter Settings" link.

The opened window contains all network connections available on your computer.

Right-click on the connection will allow you to perform various actions, they are also available on the toolbar at the top of the window:

Disable the connection so that it is saved in the network settings, but it has been closed access to it.
Connect and disable from the network.
Check the status of the network, useful if you are experiencing a connection difficulty.
Diagnose problems or connection malfunctions. This is an automatic troubleshooting tool, resets the connection to its default state.
Check the connection properties. Here you can change the settings of the network adapter. Use your computer to exchange with other computers, turning it into a mobile access point, or turn on / disconnect specific functions that may cause problems such as IPv6.
There is no option to remove the connection, changes in the auto-connection function or password parameters. To remove the connection, select it and press the DELETE key on the keyboard.

Attention. Windows 8.1 allows you to select the status of a network or Internet connection. It is sometimes easier to delete the connection and restore it when restarting.

If you manage the network at home or at work, you should get a complete idea of \u200b\u200bsafety and network management, including knowledge of who will use this network.

Of course a router that allows you to establish multiple basic and guest ssid connections worth a decent money, especially for small firms. But its advantages are obvious, you do not have to worry about visitors who have received random access to your computers stored on them files or shared storage in your work environment.

Many high-performance routers offer this functionality, and in the workplace it is difficult to recommend something better. Such a router is also useful at home, especially if you use joint network storage, for example, connected to your router NAS drive or hard routine USB diskwhere you save backups and private files.

The main thing is to always make sure that the router has two passwords: one to administer through the interface and the other for Wi-Fi. These passwords should always be different. If you have a router that supports a multiple SSID, each must have its own unique password. It - the best way Guarantee, as it is possible that you have excellent security on your network.

prompt. To create a secure password, make sure that it consists of at least 12 characters and includes a mixture of uppercase and lowercase letters, numbers, and symbols. You can also use some numbers and symbols to replace the letters, for example, "5" instead of "d", "1" instead of "a" and so on.

Wi-Fi network protection.

When you create your Wi-Fi network, before you can stand the question - what to use the type of security. You can choose WEP, WPA-Personal, WPA2-PERSONAL, WPA-Enterprise or WPA2-Enterprise. Since they are all - a combination of letters and numbers, it would be nice to learn what everyone means. There is a temptation to choose the main type of encryption, such as WEP, because it allows the use of short easily memorable passwords. But a short password is unsafe. The higher the encryption level, especially complex requirements for the default password.

It suffices to say that WEP, WPA, and WPA2 are far from being safe, especially in business space, and quite on teeth experienced and decisive hackers. Although if your router does not offer additional security options, such as AES encryption or RADIUS authentication server - you will never be completely protected.

Each new Wi-Fi added type of safe encryption and authentication makes the password longer with more stringent requirements. The easiest is entered into the computer only once; But more complex requires constant input.

What do you have in your network? How important are your files and documents? Are you really a goal for a hacker? Most enthusiasts and IT specialists have the same file types in their networks as any consumer, but they have business files. However, only if you store especially important data on your network (for example, you work in a high-tech industry or for a government institution), you are likely to go for a hacker. Although past years have shown that the embezzlement of government data is much more likely from the inside than outside.

Even if you never go for a hacker, it is still better to use a balanced parameter. WPA2 encryption is recommended for home users. The minimum password length in it is slightly longer easy to memorize, but safety professionals always recommend having long passwords. Yes, and no one comes from writing your password on a piece of paper, it is unlikely that someone physically burst into your building to gain access to your Wi-Fi network. And WEP and WPA simply do not give enough security.

Manage the use of data in a mobile broadband network.

If you use your computer on a mobile broadband connection (3G / 4G), you probably want to be sure that they did not exceed their use limits.

Windows 8.1 can help you monitor and limit the amount of data used by showing it in the connections network panel. When you connect from mobile broadband networkWindows shows until now the data used. If you are on a monthly contract, with a data set, the meter can be reset each month by clicking on RESET.

However, you will need to enable this feature for each network (can also be done for Wi-Fi networks):

Open PC settings.
Click on the Network settings.
Click on the network name for which you want to display data use.
In the Data Usage section, switch the switch under "Display My Data Use in the Networks list" and, optionally, you can note that Windows 8.1 processed this network as a measured connection. This installation prevents the departure and getting Windows And your applications of too much data, which saves from excessive traffic costs.

The tiles window allows you to determine the maximum amount of data that live tiles can use during the month. Once this limit is achieved, live tiles on a mobile broadband connection will not be updated anymore.

For comfortable work on the Internet, the speed and stability of the network connection are important.

Sometimes problems with connecting to the network - as a result, files are downloaded or web pages are downloaded. To find out why the problem appeared, check network connection.

Spend built-in diagnostics

Check out the network access using Windows troubleshooting and wireless diagnostic software for MacOS. Choose operating system:

Windows 10.
Windows 7.
macos.

Run network troubleshooting tool:

Click Start → Control Panel → Network and Internet → Network and Shared Access Control Center → Troubleshooting → Connections to the Internet.

Follow the instructions on the screen.

Use the program « Wireless diagnostics» .

For more about it, see the Wireless Environment Wire Analysis on the service website apple support.

Use network utilities

Get information to diagnose the network using the Ping, Pathping / Traceroute and Telnet utility. Select the operating system:

Windows 10.
Windows 7.
macos.

Ping.

Pathping.

Telnet

First, set the Telnet client:

Other utilities

Run the utility:

Ping.

Using the Ping utility, you can check the quality of the network connection. The utility determines the delay time between the query to the server and the answer, as well as the loss of data packets. The smaller the reception time and the number of lost packets, the faster the web page opens or the film will be loaded.

To check the network connection:

Pathping.

Using the Pathping utility, you can determine which intermediate network node is delayed or data packets are delayed.

To check the intermediate nodes of the network:

Telnet

Using the Telnet utility, you can check if the computer has the right to connect to the server.

Initially, turn on the Telnet client. For this:

Now you can check access to the server:

Other utilities

Choose a utility depending on the purpose:

IPConfig - find out the IP address, subnet mask and others network settings;

GetMac - view network connections, network adapters and their physical addresses;

Tracert - Get a chain of nodes through which the IP package passes.

Run the utility:

Go to the Start menu and type the command line or cmd.exe in the search row. Run the application.

In the window that opens, enter:

ipconfig / all - for ipconfig;

getMac / V - for getmac;

tracert.<адрес сайта> - For Tracert.

Press ENTER.

To copy information, anywhere open window Right-click and select Allocate All. Then press ENTER.

Copy text can be inserted (Ctrl + V) in text file or letter.

I already wrote about what is and how to check, under what address you sees the outside world. However, often this information is not enough to understand what is still assigned to your network card, as well as to diagnose the connection problems. I will give a list of commands that you can use. (Also, on my site you can read about visual setting)

First you need to open command line. This is done like this: Press the Start button, select the "Run" item.

Alternative way - you need to press the Win key (between Ctrl and Alt) and R at the same time, this method also works on Wasta

Appears window to which you need to enter cmd. and click OK

The same command line appears.

In it, you can dial and "enter" commands by pressing ENTER. The results can be copied - if you click the right piece, you can select the desired piece, then you need to click on the right mouse button again.

Ping team

The first team with which you need to meet - this ping.verifying the availability of a specified address. Enter the command ping 127.0.0.1. Should turn out something (if the team is not ping. Not working, then perhaps solving the problem will help the CMD No Command error manual:

C: \\ Documents and Settings \\ Administrator\u003e Ping 127.0.0.1

Exchange packages from 127.0.0.1 32 bytes:

Answer from 127.0.0.1: number byte \u003d 32 Time

Ping statistics for 127.0.0.1:

Minimal \u003d 0 ms, maximum \u003d 0 ms, mean \u003d 0 ms

C: \\ Documents and Settings \\ Administrator\u003e

As we can see, 4 packages were sent to the address 127.0.0.1, and they all achieved goal. What was the address and why was I sure that the packages would reach? The answer is simple - the packets were not sent anywhere, but remained on your computer. This address is specific and used for loopback - packages that are not leaving anywhere. Excellent, we can now "propagate" the address of this site: 212.193.236.38

C: \\ Documents and Settings \\ Administrator\u003e Ping 212.193.236.38

Exchange packages from 212.193.236.38 32 bytes:

Answer from 212.193.236.38: Number byte \u003d 32 Time \u003d 3ms TTL \u003d 55

Ping statistics for 212.193.236.38:

Packages: Posted \u003d 4, obtained \u003d 4, lost \u003d 0 (0% loss),

Approximate reception time in MS:

Minimum \u003d 3 ms, maximum \u003d 3 ms, average \u003d 3 ms

C: \\ Documents and Settings \\ Administrator\u003e

Only one difference can be seen - the packages have reached not instantly, but for 3 milliseconds. I hope you also had no delay when delivering packages, and most importantly - you did not see line lines

Timed out request.

The appearance of such lines means that part of the packages is lost. This indicates problems on a line or non-server, to which you appeal.

Ipconfig command

Next important team - ipconfig. Enter it. I got like this:

Ethernet - Ethernet Adapter:

C: \\ Documents and Settings \\ Administrator\u003e

In this case, it turned out the address 192.168.17.139. You can specify this address too (you ping your own) - packages must come in instantly. The main gateway is the address to which the computer sends packets without finding the right address in its network. So, in my case, all packages, except for packages for 192.168.17. * Will be shipped at 192.168.17.240, and that tube must decide what to do with them and send them further. Note: Local Network, that is, the addresses, packages for which are not sent to the gateway, is determined by means of a mask - a talker in the last place and 255 on all previous ones just means that it may be an arbitrary last number in the IP address.

One of the standard actions when searching for connecting problems - to propagate your gateway. If packets do not reach it, then, apparently, the problem is somewhere near, for example, damaged or badly stuck a network cord. It is also worth knowing where the computer is physically located with your main gateway - the provider, somewhere in the house, and maybe it can be in your apartment. Note: Some computers are configured not to respond to requests. ping teams. Therefore, the lack of ping is not a 100% guarantee of the lack of communication with the address.

More detailed information You can get a team iPConfig / All.. I managed:

C: \\ Documents and Settings \\ Administrator\u003e IPCONFIG / ALL

Configure IP Protocol for Windows

Computer name. . . . . . . . . : Sander.

The main DNS suffix. . . . . . : Mshome.

Type of node. . . . . . . . . . . . . : Mixed

IP Routing included. . . . : not

WINS proxy included. . . . . . . : not

The procedure for viewing DNS suffixes. : Mshome.

Ethernet - Ethernet Adapter:

DNS suffix of this connection. . : srcc.msu.ru.

Description. . . . . . . . . . . . : Broadcom 440x 10/100 Integrated Controller

Physical adress. . . . . . . . . : 00-16-D4-63-03-65

DHCP is enabled. . . . . . . . . . . : Yes

Auto-tuning is enabled. . . . . : Yes

IP address. . . . . . . . . . . . : 192.168.17.139

Subnet mask. . . . . . . . . . : 255.255.255.0.

Main gate. . . . . . . . . . : 192.168.17.240

DHCP server. . . . . . . . . . . : 192.168.17.240

DNS servers. . . . . . . . . . . : 212.192.244.2

212.192.244.3

C: \\ Documents and Settings \\ Administrator\u003e

Self useful information I highlighted fat. I allocated me a dynamic address based on my MAC address or physical address. My is 212.192.244.2 and 212.192.244.3.

Other teams

Team tracert. Allows you to trace the path of the packages from your computer to the target. Try, for example, to put the way to this site: tracert Site. Rows in the trace output have points through which the package passes on its path. The first point will be your gateway. Using the Tracert command allows you to find a source of problems when communicating with any address. Packages sent by the Tracert command have a TTL - Time to Live - a whole positive number. Each router on the path reduces this figure by 1, if the TTL drops to zero, then tracing ends. The default is the initial TTL equal to 30, set another value option -h.

Setting up a network connection in compliance with all instructions is not yet warranty uninterrupted Internet access. The reasons for which the network ceases to work is varied and not always obvious. Let's talk about what can cause an Ethernet connection failure and how to fix it.

Why Windows 8 does not work network connection via cable

Reasons associated with equipment:

damaged or poorly affected the network cable;
the length of the cable segment between network nodes (more than 100 meters) is exceeded;
network devices are incorrectly uncovered;
the network gateway is not working or incorrectly configured (the device through which the computer connects to the Internet);
the cable is not connected to the computer network card;
network card is defective or not installed (there is no driver);
near cable, computer or other network device (Router, Switch) There is a source of electromagnetic interference.

The reasons associated with the settings:

networks are not running windows services;
changed WinSock configuration (Winsock is windows structuresthat control the access to applications to network Services);
incorrectly indicate connection parameters;
the network adapter is turned off to save energy;
the connection is blocked by incorrect settings for protective programs (firewall or Windows firewall);
connecting to the network (or only to the Internet) is limited by the administrator;
Windows Infected malicious programswhich block access to the Internet.

If the connection is limited to individual applications, for example, only a browser:

the application enters the Internet through a proxy server that is unavailable;
the application is blocked by Windows Firewall, Firewall or Computer Administrator;
in the context of the application, malicious scripts work.

We restore the operation of the cable network

Eliminate equipment malfunctions

If there is no connection completely, periodically disappears or loses data, start checking with network cable. Make sure the integrity of its isolation and the absence of fades. Check the quality of the fastening of the connectors.

If you configure the connection primary, make sure that the cable is properly affected (the conductors are connected to the desired connector contacts). Below are the schemes of crimping:

to connect a computer device (switch or router);
to connect a computer computer.

The check is relevant only when you enclosed the cable yourself. Cables purchased in the store are already with connectors, are non-working rarely enough.

Check if the network is folded correctly. Connecting to the Internet can be direct (the provider cable is connected to the computer's network card) or through the gateway (router or other computer). The switching method and access settings can be found in the technical support provider.

When connecting via the router, it is important not to confuse the connection jacks: the provider's cable is inserted into the "Internet" or "WAN" jack, and the "LAN" jacks are connected network cards computers.

If there are still no connections, check if it is set to Windows Network driver.

Open the Device Manager - in Winows 8 it is called from the context menu windows buttons (Start).

Expand the list Network adapters"And check whether the Ethernet card is in it. If it is defined as an unknown device, go to the site of its manufacturer, using another Internet connection, download and install the driver.

After that, open the Card Properties through the context menu in the Device Manager

and make sure it works fine.

In the following, open the "Power Management" tab and uncheck the checkbox from the "Allow shutdown to save energy", otherwise the connection will be interrupted.

If, after installing the network driver, the connection is still limited, check if there are not near the computer, the router or the installation of the network cable device, creating interference: radiotelephones, powerful power lines, microwave ovens. Try moving away network hardware from such places.

Check Windows Network Settings

Use network diagnostics tool

The "Problem Diagnostics" tool allows you to identify and eliminate the causes of various network failures Winows 8. To run it, click on the "Network" icon in the system tray and select the item item.

If the problem is not automatically eliminated, the diagnostic tool will indicate that it caused.

In this case, the reason will have to search and correct in other ways.

Run service

The fact that the Internet connection is limited or missing, the failure is to blame network Services WINDOVS. To check their work, open the Office Management Application:

in the context menu windows buttons (Start) Click "Run" item;

enter the "Run" command in the "Open" field Services.msc. and click OK. The application will start.

In the service management program, check out the following components:

DHCP client;
DNS client;
Network security interface service;
Network Setup Service.

If these Windows services are not running, the connection will not be created or will be limited only local Network - without internet access.

To configure the auto-timing of network services, together with Windows, open the properties of each of them (through the context menu).

Select the "Automatically" parameter from the Launch Type list. To start the service immediately, click the same button in the Status window section.

Reset WinSock settings and TCP / IP protocol

This operation restores the state of network structures - sections windows registry 8, where WINSOCK configuration is stored. Console is used to reset windows utility - Netshell.exe. Accordingly, it starts through the command line (from the administrator).

To reset WinSock and TCP / IP protocol, first execute two instructions in the console: Netsh Winsock Reset. and Netsh int ip reset.

After that restart the computer.

Correct connection settings errors

To check the connection settings, enter the Windows button (Start) context menu and open the Network Connections folder.

Right click Open the context menu of the connection and click the Status item.

The following window will display the basic connection parameters:

DHCP protocol (assigns the IP address and other settings to work in TCP / IP networks) - on or not;
IPv4 address - If it starts with 169.254 (APIPA address range), it means that the connection does not receive the valid IP from the DHCP server. Such a connection will always be limited and will not receive Internet access.
Subnet mask - assigned automatically depending on the IP group.
The default gateway is an IP network device used as a gateway for this compound.
DNS server - server address associated domain names IP addresses of hosts.

To go to the settings, click the "Properties" button in the Status window. In the next window, check in the list of "IP version 4" components and click "Properties" again.

If the connection does not receive IP and other settings automatically, write them manually. If the computer is connected to the Internet directly (without a gateway), find out the parameters from the provider. When connected via the gateway (router), one of the local range addresses is assigned as an IP to which the gateway refers. For example, if the router address starts at 192.168.1, the connection address should begin on the same numbers.

The "Main Gateway" field indicates the IP router.

Information on the disconnection of third-party firewood can be found from the reference to it.

Eliminate other problems

Connect B. corporate networkwhich is limited by the administrator, it makes no sense to try to reconfigure - it will not work anyway. And if it is limited to the house, and this is definitely not the work of your loved ones, it is possible that the virus started in the system. For the same reason, access to the network can be closed for individual applications. To solve the problem, scan the system with antivirus and check the network settings again.

If the failure occurs only in one application - check the network access settings in it and the limit rules for it in Windows Firewall. If the source of the problem is not found - reinstall the program.