How to use Netstat on Windows 10 to troubleshoot your connection issues



Maintaining a good Internet connection is essential on any device. Much more on a PC that we use to telework, or to do schoolwork. But there are times when we notice that something isn't working well. It's time to turn to Netstat to fix your connection problems.

Netstat is a Windows tool focused on the networks connected to the computer. It displays countless information in real-time with everything in and out of your PC.

It is an application for experienced users, who control the technical concepts related to IP addresses, TCP connections, ports, etc. Still, any un knowledged user can use it to know which devices are connected to the router, who is accessing your PC or to check if the connection is working properly.

Let's show you how to use Netstat in Windows 10 to troubleshoot your connection issues.

Please note that this is an informative tool. It shows you information about the networks your PC uses, that is, it tells you where the problem is, but it doesn't fix it. For that, you will have to use other tools, or change the Windows settings.



Some basics

As we have mentioned, some basic network management knowledge is needed to understand the data offered by Netstat.

We're not going to go too deep because this is a hands-on tutorial and not a networking course, but we're going to explain certain terms needed to be able to use Netstat.

All devices that connect to a network receive a unique identifier, a kind of identity card, called an IP address. This IP address is unique worldwide (if the network is global, such as the Internet), and serves to unequivocally identify the device within the network. It can be IPv4 or IPv6, longer, but they all refer to the same thing, identifying your Internet connection.

If you want to know the real IP address of the PC, mobile or tablet with which you are reading this tutorial, go to the MyIPwebsite, and it will tell you, including data such as your location, your carrier, your browser, and much more. Indeed, anonymity does not exist on the Internet.

This IP address is an external address, that is, it is used to communicate with the outside, and is assigned to us by the operator.

There are also IP addresses that we could call internal or local, because they are created by our devices, or the router, for personal use.

For example, most routers assign this IP address to devices that connect to them: 192.168.1.XXX, where XXX is a different number for each device

Thus, your PC may have the IP address 192.168.1.35, and your mobile address 192.168.1.44. These are internal addresses that the router uses to allocate Internet bandwidth to each connected device, but when communicating with the Internet they all use the same, the external IP address that we mentioned earlier.

At any given time the router may be communicating with dozens of different devices. For example, if you have 5 web pages open, each website is on a different server with its own IP address. And if you also have multiple mobiles connected, console, Chromecast, TV, etc., sometimes there are dozens of connections handled by the router.

The data that is sent or received through each of these connections, arrives through the ports (port). A router can use hundreds, thousands of them.

With Netstat we will see many results that have the format: 132.234.12.45:8000. He's telling us that there's a device connected to our router with IP address 132.234.12.45, and it's connected via port 8,000.

You will also see the word TCP or UDP repeatedly many times. They refer to the communication protocol (rules) used on the Internet. All networks have to use the same protocol to understand each other.

With this basic data, we can now see how to use Netstat in Windows 10 to troubleshoot your connection issues.



What is Netstat

NetStat, or Network Statistics, is a Windows 10 tool to check the status of the networks to which your PC connects.

It is a command tool, which means that it works with text commands that need to be typed with the keyboard.

To launch NetStat, open the Windows browser (the Magnifier in the Taskbar), and search for Command Prompt. Get it going. A text window will appear with a blinking cursor, waiting to receive your orders. Let's see what we can do.



The requested operation requires elevation

When you try the various Netstat options that we're going to see, the order may not work in some case, and a strange message appears: The requested operation requires elevation.

It's a nefarious translation that what you're telling us is that we need Administrator permissions to be able to use that order.

Active connections

If in Command Prompt you type netstat and press the Enter/Enter/Enter key, you will see all the active connections currently available to your PC and the router to which it is connected.

We see a few 127.0.0.1 connections with different ports. Address 127.0.0.1 refers to your own device and is showing you the ports of the router you are using.

Then we see several 192.168.1.35. As we explained are internal addresses that the router assigns. In this example, the router has assigned your PC position 35, to differentiate it from your mobile, console, or another device that you connect to the Internet.

You can see how the PC is using different ports (10.443, 10.456, etc.), with different remote addresses, which in this case are web pages that we have open in the browser.



In the Status column, Established indicates that the connection is active. Close_Wait that the remote device has closed the port (the connection is lost) and Time_wait, that we have closed it.

Therefore, with a simple order, we are already getting a lot of information. We see that the connection works if we get IP addresses on average that we open web or use apps or games that connect to the Internet.

We also see which IP address the router has assigned us, the ports we are using, and the IP addresses of the servers or websites to which we connect.

This can also help us detect intruders or malware. For example, if we are not connected to anything and Netstar tells us, yes, or we check that we are often connected to an IP address from China or Russia that we do not identify.

But you have to know how to understand this information because sometimes Windows itself or apps often connect to update, and valid connections that we don't identify occur.



Fully qualified domain names

To try to identify the remote connections that reach our PC, we can see the fully qualified domain names of those IP addresses (FQDNs).

Now we can see typical things, like Facebook accesses even though we don't use Facebook (it's snooping around all sites), amazon cloud access (Amazon Music is ringing while we're doing the tutorial), access to Google DNS, etc.



IP addresses and ports

With the above command, in the Remote Address column, we get the names assigned by the network to the connected devices, to identify them.

If you want to see your IP address and the ports being used, in Command Prompt type: net start -n

If only one port is used, as we see here (port 443) it is because everything enters through the same site, as can be multiple web pages through the browser.



Global statistics

With the command: netstat -e

We obtain global statistics on network usage, as long as we have Open Command Prompt:

We can see the bytes received and sent. But the most important data is discarded packets, errors, and unknown protocols. If they give values of 0, as we see in the image, it is that the connection is stable and has no problems. If there are errors or packets discarded, the connection is choppy, and there is some failure to.

All connections and ports listening

With the above orders we have seen the connections that are active at all times, that is, that they are sending or receiving data. But we may want to see all connections, including inactive ones. As well as the ports of our router that you are listening to (Listening), that is, waiting for possible connections. It's a way of knowing the ports we have in use.

To do all this you have to use the command: netstat -a



Online apps

So far we are obtaining technical data that have value for connoisseurs.

A very useful option that clarifies many mosques, is the order: netstat -b

What it does is show us in real-time the programs that are connected to the networks that we are using, as well as the port they use:

As we see in the example, Chrome, Firefox, and Brave browsers, as well as NVIDIA drivers on the graphics card (container), or Amazon Music, are sending or receiving data.

It's a good way to know if an app spends more time on the connected account, or if any unknown apps are sending data.

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