BreakingModern — I’ve been using today’s app pick since my first Android phone back in late 2009. It was the Droid on Verizon, and if you went from the old Windows phones to that back then, you were a very happy camper. When I’m doing network stuff for work and friends, I always needed a good scanner. Network Discovery by Aubort Jean-Baptiste is that network scanner, and it’s the only one you need. This app not only does network discovery, but also port scanning.
Mmm … Settings
This app is everything a great Android app should strive to be. Light, functional and the couple things it does, it does very well. This thing is only 256K and works on most any device running Android 3.0 and up as of the latest update. Keep in mind, when I say “latest,” I mean in the last couple of years. Network Discovery hasn’t been updated since October 2013, but when an app is this small and only does a couple of things, once you get it right, you don’t really need to update it.
Turn your Wi-Fi on, and then open the app. There is an option in the discovery settings that allows for mobile discovery. It says it will scan over EDGE or 3G, but gives very strange results, if any. For best results, this is a Wi-Fi only app.
Once it finds the network you want to scan, tap the discover button. This is going to scan the IP range of the network you are connected to, showing all the different devices connected to that network. Once it’s finished you can tap on any of those devices to get more information on them and do a little port scanning.
For our example we’re going to use my Netgear router. Tap that and you’ll go to the scanner screen. This will show all the open and closed ports on the device. From here we can see that my router has TELNET and a couple of HTTP ports open.
In the closed tab you can see all the ports that are closed on the router. Let’s take a look at another device, a device that isn’t a router.
The internal IP ending in .1.7 is the TV. I know that because it says Vizio Inc. under it. Tap that and let’s see what ports this thing has open. It’s actually quite reassuring this TV doesn’t have any wide open ports sitting out there waiting for someone to scan and find. It does have SSH and TELNET of course, but since the ports are closed, they are unavailable for a connection.
We can test this by tapping connect. You can set the credentials it will connect with in the settings of the port scanner options. The default, of course, is root. Let’s see what the TV does if we try to connect to it via SSH using root as the username. Of course, in order to SSH to something, you’ll need to have an SSH client of some type installed. The one I recommend is ConnectBot. This is another great Android app that’s been around since the early days, does one thing well, and is completely awesome. Install it, then we’ll try to establish an SSH connection to the TV.
Just as I thought, connection refused. This is exactly what we would hope to see. Good secure stuff right there. Thank you, Vizio.
Let’s take a look at one more device, and then we’ll call it good. This time we’ll do a manual scan. How about a manual scan of the new Chromebook I’m writing this article on? Here we go.
Since its address did not show up in the normal network discovery, we’ll type it in manually. Hit the three dots on the bottom right of the screen, and tap Scan IP.
Of course zero open ports and 29 closed ones. Good job Chromebook!
If you need a nice, easy-to-use, lightweight and free network discovery app and port scanner for Android, look no further than Network Discovery. Download it for Android on Google Play. You can also get it here on Github and compile your own.
All Screenshots: Mat Lee
Featured/Header Image: “Radar” by BenFrantzDale via Flickr Creative Commons