Check the current status of network connections. Commands for checking and correcting network settings

I already wrote about what it is and how to check under what address the outside world sees you. However, often this information is not enough to understand what address is assigned to your network map, as well as diagnose connection problems. Here is a list of commands that can be used. (you can also read about visual customization on my website)

First you need to open a command prompt. This is done as follows: 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 Vista

A window appears in which you need to enter cmd and click OK

The same one appears command line

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

ping command

The first team to get to know is ping A that checks the availability of the given address. Enter command ping 127.0.0.1. You should get something like this (if the command is not ping does not work, then perhaps the instruction to fix the error cmd no command will help solve the problem):

C:\Documents and Settings\Administrator>ping 127.0.0.1

Packet exchange from 127.0.0.1 to 32 bytes:

Response from 127.0.0.1: number of bytes=32 time

Response from 127.0.0.1: number of bytes=32 time

Response from 127.0.0.1: number of bytes=32 time

Ping stats for 127.0.0.1:

Minimum = 0ms, Maximum = 0ms, Average = 0ms

C:\Documents and Settings\Administrator>

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

C:\Documents and Settings\Administrator>ping 212.193.236.38

Packet exchange from 212.193.236.38 to 32 bytes:

Response from 212.193.236.38: number of bytes=32 time=3ms TTL=55

Response from 212.193.236.38: number of bytes=32 time=3ms TTL=55

Response from 212.193.236.38: number of bytes=32 time=3ms TTL=55

Ping stats for 212.193.236.38:

Packets: sent = 4, received = 4, lost = 0 (0% loss),

Approximate round-trip time in ms:

Minimum = 3ms, Maximum = 3ms, Average = 3ms

C:\Documents and Settings\Administrator>

You can notice only one difference - the packets did not reach instantly, but in 3 milliseconds. I hope you didn't have any delay in the delivery of packages either, and most importantly, you didn't see lines like

Timed out request.

The appearance of such lines means that some of the packets are lost. This indicates problems on the line or not on the server you are accessing.

ipconfig command

The next important command is ipconfig. Enter it. I got it like this:

Ethernet to Ethernet adapter:

C:\Documents and Settings\Administrator>

In this case, the address is 192.168.17.139. You can also ping this address (you ping your own) - packets should reach instantly. The default gateway is the address to which a computer sends packets when it cannot find a suitable address on its network. So, in my case, all packets except packets to 192.168.17.* will be sent to 192.168.17.240, and that computer should already decide what to do with them and where to forward them next. Note: the local network, that is, those addresses to which packets are not sent to the gateway, is determined using a mask - a zero in the last place and 255 in all the previous ones just means that the last number in the IP address can be arbitrary.

One of the standard steps when looking for connection problems is to ping your gateway. If the packets do not reach it, then, apparently, the problem is somewhere nearby, for example, the power cord is damaged or badly plugged in. It is also worth knowing where the computer with your main gateway is physically located - at the provider, somewhere in the house, or maybe we can in your apartment. Note: some computers are configured not to respond to requests ping commands. Therefore, the absence of a ping is not a 100% guarantee that there is no connection with the address.

More detailed information can be obtained by command ipconfig /all. I managed:

C:\Documents and Settings\Administrator>ipconfig /all

Configuring IP for Windows

Computer name. . . . . . . . . : sander

Primary DNS suffix. . . . . . : MSHOME

Node type. . . . . . . . . . . . . : mixed

IP routing is enabled. . . . : No

WINS proxy is enabled. . . . . . . : No

DNS suffix lookup order. : MSHOME

Ethernet to Ethernet adapter:

The DNS suffix for 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>

most useful information I highlighted in bold. gave me a dynamic address based on my MAC address or physical address. Mine are 212.192.244.2 and 212.192.244.3.

Other commands

Team tracert allows you to trace the path of packets from your computer to the target. Try, for example, to trace the path to this site: tracert site. The lines in the trace output are the points through which the packet passes along its path. The first point will be your gateway. Using the tracert command allows you to find the source of communication problems with an address. Packets sent by the tracert command have a TTL value - time to live - a positive integer. Each router on the path reduces this indicator by 1, if the TTL drops to zero, then the trace ends. By default, the initial TTL is 30, you can set another value with the option -h.

Before you write "nothing works for me", try to find out what specifically does not work for you.

If you decide to leave a message on the forum / VKontakte, please note that the message is not considered an official appeal to the technical support service, the contacts of the TP service are on home page site.

Please read at least a few posts on the topic before posting. last page- it is possible that this problem has already been solved or it is already being solved!

Diagnostic commands:

*Performed in a previously opened "command line" window. (Start -> All Programs -> Accessories -> Command Prompt)
For Windows Vista/7: Win+R ===> cmd ===> Enter
For Windows NT/2000/XP/VISTA: "Start" - "Run" - "cmd"
For Windows 95/98: "Start" - "Run" - "command".

Copy text: right click on this window - "edit" - "select" and "edit" - "copy".

ipconfig /all
nslookup
ping [host address (for example, ya.ru) ] [-n 20]
pathping [host address]
tracert [host address]

ipconfig /all shows network interface settings.
Everything that is indicated there must be checked with the user's memo (if the memo is old, then check with the data that was issued technical support). See the website for how to set up the connection.

ping [-t] shows the response time from the specified host. Large delays can indirectly serve as an indicator of a slow resource (loaded channel, weak resource hardware, and similar problems). The [-t] key is used to execute the command before the user interrupts it by pressing "Ctrl+C". By default, without this key, ping will only run four times, which is not always enough.

pathping Shows the response time and the number of missing packets along the route to the host.

tracert
For graphic display problems can be downloaded from local network PingPlotter

nslookup
Check DNS operation.

Check algorithm: Error " Network cable not connected"

1. Check the cable connection in the network card
2. Check the integrity of the cable up to the shield.
3. Call Tech. support.

The network cable is connected, but there are no incoming packets.

1. Check the cable connection in the network card (you can remove and insert the cable into the socket).
2. Disable all firewalls (firewalls), if you have them.
3. Ping the gateway (take the address from the connection settings or from the connection details in the control panel).
4. Call Tech. support.

The network cable is connected, there are incoming packets, but do not go to the internal services:

1. Disable all firewalls (firewalls), if you have them.
2. Check DNS operation (nslookup).
3. Check connection with these servers (ping)
4. Check connection with central servers. (ping online.vo, ping 192.168.0.250, ping your_gateway_address)
5. Check browser settings
5.1. Internet Explorer-> "Tools" menu -> "Internet Options" -> "Connection" -> "Network Settings" -> check if the checkbox "use a proxy server" is disabled
6. Call Tech. support.

DNS check:

The nslookup server command should return the ip address of that server. For example, the command "nslookup vo47.ru" should return the address "193.106.108.68"

Diagnostic Commands

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

Sometimes there are problems with the network connection - as a result, files take a long time to download or web pages do not load. To find out why the problem occurred, check network connection.

Run built-in diagnostics

Check network access using the Windows Troubleshooter and Wireless Diagnostics for macOS. Select operating system:

• Windows 10
• Windows 7
• macOS

Run the network troubleshooter:

Click Start → Control Panel→ Network and Internet → Network and Control Center public access → Troubleshooting → Internet connections.

Follow the instructions on the screen.

Use the program "Wireless Diagnostics".

For more information, see Analyze your wireless network environment on the service website. Apple support.

Use network utilities

Get network diagnostic information using the Ping, PathPing/Traceroute, and Telnet utilities. Select operating system:

• Windows 10
• Windows 7
• macOS

Ping

PathPing

telnet

First install 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 between a request to the server and the response, as well as the loss of data packets. The shorter the time of reception and transmission and the number lost packets, the faster the web page opens or the movie loads.

To check network connection:

PathPing

Using the PathPing utility, you can determine on which intermediate network node data packets are delayed or lost.

To check intermediate hosts:

telnet

You can use the Telnet utility to check if the computer has permission to connect to the server.

First enable the Telnet client. For this:

Now you can check server access:

Other utilities

Choose a utility depending on the purpose:

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

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

Tracert - get the chain of nodes through which the IP packet passes.

Run the utility:

Go to the start menu and type in search line command line or cmd.exe . Launch 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 Select All. Then press Enter .

The copied text can be pasted (Ctrl + V ) into text file or a letter.