Each computer that connects to your home network or the Internet can be identified with a numerical code called an IP address . This IP address may be unique in the world but it is almost always shared with other users and among many connected PCs.
In this guide we will show you how to correctly obtain the internal IP addresses (those of the devices connected to our modem or our router) and how to recover the external IP address of our connection , so as to be able to correctly configure port forwarding for surveillance services. or to access local files even remotely.
In a dedicated chapter we will also show you how to spy on local computers after obtaining the information on the IP, so that you can control any device without being physically present in front of the monitor.
This information should be used only for educational and cognitive purposes and do not presume to go further, given that Navigaweb assumes no responsibility for improper use of the proposed material. Given the vastness of the topic, this article has many references to other posts on this blog, so that you can find insights on all the issues addressed.
How to find internal IP addresses (LAN)
Before seeing how to spy on PCs or other devices in the local network, we will need to be able to correctly distinguish the internal IP addresses (assigned to each device connected via LAN or Wi-Fi) and the external IP address (the one provided by the operator to our modem).
To see your internal IP on a Windows computer, just go to the Start -> Run -> cmd path and write the ipconfig command . In the window that opens, look for the IPv4 address item under the network device we use to connect ( Ethernet card or wireless card ).
To find out the IP addresses of the other devices connected to the modem at that precise moment, simply enter the configuration panel of the same, so as to be able to view the connected devices in the Network , Network , DHCP or Devices menus .
The modem IP address (required to access the control panel) can always be obtained from the PC using the ipconfig command and looking for the Gateway item under the network card used for connection.
If, on the other hand, we want to know the IP addresses of the other devices directly from the computer, we will have to use a free program such as MyLanViewer Network / IP Scanner .
By launching this tool we will be able to view the internal 10.0.0.0.1 IP addresses of all connected devices, without having to enter the modem settings.
How to find the external IP address of a PC or smartphone
To see our IP address outside of our line, all we have to do is open a web browser and open the ipinfo.io site , the best of its kind and the most accurate that I have found.
We will thus obtain the external IP address assigned to our line by the operator, with the coordinates to detect the exact position of the detected place and a lot of information for tracking.
Used by a smartphone, it lets you know the operator associated with an IP which can be ours or any other.
The localization is partial because, if we are under the same IP subnet (such as on Fastweb network), we go out on the Internet behind the same NAT router (i.e. we all go out with the same IP address on the Internet) so it is not possible to know precisely where we are. Even if the site does not show the exact location of your home, it does allow you to see which part of the world you are connecting from, the state and the city.
How to spy on another computer
To know the origin of another IP address and see it on the geographic map , you can run a TraceRoute that can also be done from the Dos window (the cmd opened before) and write the command ” Tracert ” accompanied by the IP to be spied.
Basically, given a starting point (the computer) and an ending point (a website), there are all the routers and network points in the world that make the connection go from one point to another.
On the site seen in the previous chapter there is also the possibility to see from where an e-mail was written and locate the sender on the geographical map .
By doing so we will be able to find out (in most cases) who sent us the spam email or the anonymous email, so that we can always know the origin and possibly denounce the “nuisances”.
To spy on a person on the Internet the only difficulty is to find the external IP address of his line, which is possible only if our computer is connected to the same network even for a few seconds. In this case you can use the SmartSniff portable program from the famous Nirsoft.
After unpacking the entire contents of the compressed ZIP file, launch the smsniff.exe file and start the sniffer that captures the data packets by pressing the green button at the top left.
In the new window choose the ” Raw Sockets ” option, select the network interface used and press OK. At this point, pressing the ” Start Capture ” button and visiting a website, lines will appear on the SmartSniffer window indicating the data packets intercepted.
The ” Local Address ” column is your IP address, the ” Remote Address ” column is the IP address of the resource you are connecting to.
The ” Packets ” column will help us as it shows the number of packets transited for each connection captured.
To capture the details and the IP of a Messenger contact, you must close all programs that use the internet, start the chat with the lens and press the ” Start Capture ” button on lanc remastered.
Looking at the ” Packets ” column you should notice that, on one of the rows, this value increases more than the others; that line then indicates, in the ” Remote Address ” field, the IP address of the person with whom you chat .
With the simple chat, however, nothing is captured, to find out the contact’s IP we have to start a video chat, a shared document or you have to send or receive his file.
Finding an IP address of the local network or the external IP of the Internet connection is really very simple and this raises very big security questions: every time we connect to a new network we can be “spied” with one of the tools seen above .