How to scan your network for devices and open ports

Earlier I wrote a post about how to spot WiFi cheetahs on your network and mentioned some smartphone apps that you can use to scan your home network. The apps do a pretty good job of scanning your network automatically and giving you some detailed information on each device.

I didn’t go into the details of the apps in that post because it focuses on catching unauthorized users on your network. In this article, I will talk in more detail about these two applications that can be used on Apple or Android devices and I will also cover desktop applications that you can run on Windows and Mac. OS X.

These network scanning tools allow you to not only see all devices on your network and their IP addresses, but also view shared folders, open TCP/UDP ports, hardware MAC addresses and more . So why are you interested in this information?

Although a bit technical, this information can help you make your network more secure. For example, you might stumble across folders that are being shared on your network. Then anyone who connects to your network via cable or wirelessly can easily search the shared folders and copy that data to their computer.

By looking at the open ports of your computer or device, you can easily see if the remote desktop is enabled, an FTP or HTTP server is running, and file sharing is enabled. or not. If you never connect to your computer remotely, then Remote desktop enabled just a security risk.

Windows Network Scanner

Let’s start with a free tool for Windows PC called SoftPerfect Network Scanner. I like this tool because it is regularly updated, runs on Windows 10 and comes in 32-bit and 64-bit versions. The program also doesn’t require any installation, which means you can carry it on a USB stick or save it to Dropbox and use it on any computer you want.

Firewall blocked program

When you run the executable for your version of Windows (determine if you have 32-bit or 64-bit Windows), you may see a message saying Windows Firewall has blocked the program. Guaranteed Private network selected and then click Allow access.

After the program loads, you will need to enter the range of the network’s start and end IP addresses. If you don’t know this, don’t worry. Just click Option, IP address and then click Local IP range auto detect.

ip address auto detect

You will get a pop-up with detected IP addresses for IPv4 and IPv6 on any network card you have installed, including the virtual one. For most home users, you will only see one item listed in both IPv4 and IPv6. Unless you have IPv6 set up, you should click on the network card listed under IPv4.

ip range auto detect

You will now be taken back to the main interface, but now the IP address range will be filled in. You will see Start scanning on the right you can click to start scanning.

start scanning

However, you should first set the scan options before performing the scan. Click Option And after that Program options. Above Shared tab, the only option you might want to check is Always analyze the device. By default, the scanner will only show you devices that meet certain requirements, so the final list may not show all the devices that are actually on your network because some The device simply becomes unresponsive.

general options

The scan takes a bit longer (minutes versus seconds), but it’s well worth it if you really want to see every device on your network. The Add and Client tabs are only really useful for corporate environments where you have multiple machines on the same network and you want to get information about each computer. The Ports tab is where we can go next.

check the ports

Test Check open TCP ports then click the little sheet of paper icon on the far right of the text box. This will open another window that lists several groups of TCP ports. You want to click HTTP and Proxy and then press CHANGE key and click Database server to select all three items.

tcp port group

Back on the main screen, you will see all the port numbers listed in the text box. Go ahead and also check all the boxes for open UDP ports. At this point, click OK to return to the main screen of the program. Now click Start Scan and you will see the results slowly added to the list.

network scan results

In my tests, the program was able to find 16 devices on the network when tested Always analyze the device optional vs only 11 items when unchecked. Any entry with a plus sign to the left of the IP address means it has shared folders. You can click the + sign to view shared folders.

shared folder

The Server name column will give you an easy to understand name for the device. On the right you will see a column named TCP port, will list all open ports for that device. Obviously, numbers don’t mean much unless you know what they mean, so check this out Wikipedia page Detailed description of each port number.

If anything has ports 80 (HTTP) is listed, which usually means it has some kind of web interface, and you can try connecting to it through your browser by simply entering the IP address. port 443 for secure HTTP (HTTPS), which means you can also connect to it securely.

Mac network scanner

On Mac, you have several options. LanScan is a free app on the Mac Store that does a very simple scan and shows the IP address, MAC address, Hostname, and Provider. The free version will only list the first four hostnames in full, and the rest will only display the first three characters. A bit annoying, but probably not a big deal on most home networks.

mac lan scanner

You will also notice that it only finds 12 entries and that’s because it doesn’t have any option to scan each IP address regardless of whether it responds or not. A better network scanner for Mac is Angry IP Scanner displayed below. It is open source and works on Windows, Mac and Linux.

Angry ip scanner

By default, the program also scans open ports, which LanScan cannot do. The only problem with this program is that you have to install Java to run the program. Java is a big security risk and is disabled on most Macs by default, so you’ll have to enable it manually.

Smartphone app

I have two apps that I use, both free and one that you can download on your Apple device or Android device. Both apps are great and give you much of the same information, but each has its pluses and minuses.

Fing is a free app available on Google Play Store and iTunes store and has a great interface. You don’t have to worry about entering any range of IP addresses with these apps because they figure it out on their own. When you start scanning with Fing, you will get a nice looking device list with some basic information like hostname, MAC address, IP address, etc.


If you tap a device, you’ll get another screen where you can give it a custom name (a feature I really like), enter its location, and even add additional notes. If you scroll down you will see an option called Serviceallows you to scan your device for open ports.

finger scan service

The only downside I see with this app is that it doesn’t list out all the devices on the network. It only caught about 12 devices on my network out of the 16 that the Windows program found.

The second app I like to use is Net analyzer, available for free from the App Store. You conduct the scan by tapping the Scan button on the top right and you will get a list of all your devices within seconds.

network analyzer

Using this app, I have 15 devices, which is pretty close to the total number of devices on the network. With Net Analyzer, you’ll also see some letters colored on devices that have certain services enabled. Go green P means it’s pingable, brown REMOVE means Bonjour services (Apple devices) available, red WOOD means it’s the gateway device (router, etc) and the color is blue U means that UPNP and DLNA services are available.

You can tap on a device to get more information and perform queries on the device. Tap the Query with Tools option shown below when you tap on a specific device.

query by tools

On the next screen you will see several options including Ping, Route, Ports, Who is and DNS. Tap Gate, select Common or All of then tap Start at the top.

port scan

As the scan takes place, you’ll see which ports are open and active, and which are blocked. The app also has other tools that you can use to scan specific devices on the network to get more information.

Hopefully these tools will allow you to see the full range of devices on your network and what services and ports are open. If you have any questions, feel free to post a comment. Interesting!

Leave a Reply

Your email address will not be published. Required fields are marked *