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Network Discovery in the Palm of Your Hand

Thu, 12/20/2012 - 11:09am
John R. Joyce, Ph.D.

Network Discovery in the Palm of Your Hand

 

Fing, short for Find and Ping

While researching another column recently, I stumbled across what anyone who needs to manage or troubleshoot a network would consider a marvelous Android1 app. Before any Apple advocates tune out, let me add that I discovered there is also a version for Apple’s iOS,2 so iPhone and iPad users can take advantage of it as well. In fact, it also is available in versions for MS Windows,3 Apple OS X and Linux. This little jewel is called Fing4and was released by an organization called Overlook, operating out of Rome, Italy.

Fing, short for Find and Ping is one of the best smart phone network analysis tools that I’ve encountered. It is an outgrowth of the popular network utility Look@LAN Network Monitor,5 which was developed by Carlo Medas. Not content with the laurels that Look@LAN Network Monitor had earned, Carlos and a team under the banner of Overlook basically went back to the drawing board and used the knowledge they’d gained from writing Look@LAN to write a new multi-platform application. The initial fruits of their labors was a new free command line cross-platform tool targeting the Windows, Linux and Mac platforms called Fing.

Their development work continued, resulting in highly successful versions of Fing incorporating a graphical user interface (GUI) for Android and iOS devices. As of this writing, there have been over 1.5 million downloads of the Android version alone. While a GUI version of the initial program is in the works for the classic platforms, in this column I will focus primarily on the smart phone version. As a minor disclaimer, let me state that the testing I performed was on an Android-based Motorola Defy smart phone, so screen appearance and functionality might be somewhat different on other devices, but Overlook appears to be working hard to keep both of the app versions in reasonable parity.

 

Fing home
Illustration 1: Main screen of Fing as it appears on an Android smart phone
Fing network information window
Illustration 2: Fing network information window
 Fing node detail window
Illustration 3: Fing node detail window
 Fing Ping window
Illustration 4: Fing Ping window
 Fing Traceroute window
Illustration 5: Fing Traceroute window
 Fing 'Wake on LAN' window
Illustration 6: Fing 'Wake on LAN' window

The app launches very quickly, perhaps in part because it does not launch any update scans until you tell it what you want it to do. The initial values displayed represent the network status as of the last scan. An example of this screen, as it appears on an Android-based smart phone, is shown in Illustration 1. To trigger a scan, just tap the refresh icon shown at the top of the screen. A status bar will appear under the network name and will show the progress of the scan. Entries are updated as the nodes are processed. On repeat scans, Fing does not remove any entries from the list, instead it adds any devices that have joined the network, updates existing devices with any changes, and grays out any devices no longer on the network, consolidating them at the bottom of the list.

The top block of data identifies the scanned network. By default, the SSID of the network is displayed at the top left with a node count of devices on the network at the top right. The first number represents the number of nodes currently on the network and the second number represents the number of unique nodes that have been connected to the network. If you tap this field, Fing opens another window with more detailed information about the network. First off, below the SSID is a field where you can enter a descriptive name for your network, as well as additional notes about it. Below that are fields to display information such as:
• Network type (e.g. ‘Wireless network’)
• Network IP address
• Last discovery date
• Last change date
• Local address scanned from
• IP address of Gateway
• IP address of primary DNS6 server
• BSSID
• Network speed
• Access type (e.g. ‘Internet’)
• ISP name
• Internet address

This screen also allows you to modify the sort order of the start-up node window. By tapping on the Sort order field you can sort the nodes by:
• IP address
• State
• Name
• Vendor (vendor name associated with MAC address)
• MAC address7
• Last change

I can see where some of these options would be particularly useful when troubleshooting a network. However, for general review of your network, sorting by Name or State is probably the most useful. My current leaning is to default the display to the State option, which sorts all missing devices to the bottom of the display and sorts the active nodes by ascending IP address.

If you happened to have tapped on any of the above information fields, you may have noticed a very useful feature of Fing. Tapping on these information fields copies the displayed information to your device clipboard. From there, it can be inserted into other fields in Fing or into other applications.

Back to the initial network screen, each node in the list consists of an icon representing the device type at the far left and four pieces of information about the node. The top left item is the device’s IP address, with the MAC address of the device displayed beneath. The top right item is a device name and can be a user-assigned device name, a host name, or a name derived from a default device type. Below this value is a manufacturer name derived from the MAC address.

As with the network name, if you tap on a node in this list, a detail screen will open. The top field of this screen allows you to enter an explicit name for the node, along with additional notes. Below that are displayed a number of pieces of information about the node. The exact entries will vary with the specific device, so some of the entries shown below, such as the NetBIOS entries, may not appear in the listing for a given device. However, the following pieces of information about the node will generally be displayed:
• IP Address
• MAC Address
• Hostname
• Vendor
• NetBIOS Domain
• NetBIOS Name
• NetBios Role (e.g. Fileserver)
• First Seen
• Last Change

Below that are entries for the following functions:
• Log
• Scan Services
• Ping
• Trace Route
• Wake on LAN

Tapping on the Scan Services entry opens a Service Scan window and scans the selected node to determine what services are running on it. Upon completion of the scan, the top field displays the node name and the number of services identified on it. Below that, in the same field, are displayed the IP Address, Host Name and MAC Address of the node. The services identified are then displayed in individual fields beneath. The left-most entry in these fields is the port number that the service is monitoring with the service name displayed to the right. Underneath the service name is displayed a more descriptive name. An example shows port 80 with the name http and the descriptive name World Wide Web HTTP. Another example shows port 21 with the name ftp and the descriptive name File Transfer Protocol.

Tapping the service entries will open another window. For example, tapping the netbios-ssn (NETBIOS Session Service) entry opens a window with the header 139 netbios-ssn. Below this header are two fields displaying Test TCP Connection and Copy to clipboard, respectively. If you tap the Test TCP Connection field, Fing will attempt to connect to the device and open another window allowing you to enter information to transmit to the connected service.

If the selected service entry has an arrow on the right side of the field, it will offer you additional options as well. For example, if we tap the ftp field, it opens a window with the header 21 ftp. In addition to the two options described above, it displays two additional entries. The first of these is labeled Connect with FTP client and the second with Connect with FTPS client. If you have an FTP client installed on your device, it will then launch it for you. If you don’t have one installed, the Android version will notify you of this and offer to download one from Google Play. I suspect that the iOS version would do the same from the Apple Store. If I’d tapped 23 telnet instead, it would display the additional option Connect with Telnet client.

Tapping the Ping entry will run a series of ping tests against the service. Upon completion, the window header will display the host name and the average ping time. Below it will be displayed the following itemized details:
• Average ping
• Packet Loss
• Minimum pingtime (ms)
• Maximum ping time (ms)
• Standard deviation of ping time (ms)
• Estimated hops to target.

Tapping the Trace route entry will run a trace route test to the service. Upon completion the window header will display the host name and the number of hops identified. Below it will be displayed an itemized lists of the nodes traversed, including their IP address and host name.

Tapping the final entry, Wake on LAN,8 opens a Wake on LAN window which displays the following information for the target:
• Profile name
• MAC Address
• Local network broadcast select
• Target network IP address (e.g. 192.168.0.0/24)

At the bottom of this window are two buttons, Delete and Send. Tapping the Send button allows you to send what is known as a Magic Packet, which will trigger the LAN card of the receiving device to fully power-up the receiving device, usually a computer.

The Ping, Trace route, and Wake-on-LAN functions also are available from the Fing configuration page, accessible by tapping on the gear button on the start-up/node page.

The Windows version of Fing and, presumably, the Linux and OS X versions also are very easy to install and, while not as visually impressive, can still extract a great deal of useful information regarding your network. As of this time, while a GUI is apparently in development, I have no idea when it might be released.

Keep in mind that all of these tools are completely free. Unlike many Android and Apple apps, Overlook carefully decided not to use an advertising support model for this tool. It is their intent that all versions of the Fing, including the desktop version, remain completely free. Their business model is to provide a subscription extra-value umbrella over Fing called Fingbox. The purpose of Fingbox is to allow you to review the status of your network interchangeably from all versions of Fing, as both the network status and any configurations that you apply to the view are automatically synced across all devices you’ve defined.

Fingbox also allows you to run Fingbox Sentinels. Sentinels are implemented using a special desktop version of Fing called Fing for Console. This is a cross-platform application that can be run on Windows, OS X and Linux systems. The purpose of these Sentinels is to monitor the status of your network and push changes in its configuration to the cloud, where they can be accessed via your other devices running Fing. The other advantage of pushing this network status to the cloud is that you can then access and monitor this status through the Web using any HTML5-compatible browser. As this is obviously sensitive network information that Fing is transferring, all communication is encrypted using either HTTPS or SSL. The information regarding your network that is stored on Overlook’s servers is reportedly encrypted using 256-bit SSL suite encryption algorithms.

Fingbox is available under a variety of licenses, targeting different purposes. The lowest cost option is Fingbox Home. This is available for $3.99/month or $39/year and provides support for an unlimited number of network nodes, but only 5 Sentinels and 10 network slots. Presumably the middle cost option is Fingbox Pro. This is available for $6.99/month or $69/year and provides support for an unlimited number of network nodes, 50 Sentinels and 100 network slots. Presumably, the top-tier license will be Fingbox Enterprise, listed as coming ‘soon.’ The price for this option has not been set, but will include support for an unlimited number of network nodes and an unlimited number of network slots.

All of these options support Sync and Backup on any device. While Fingbox definitely looks as if it would be useful for companies and other organizations, I’m not sure if it would be of that much value for a home network. If you have a lot of network activities going on in the background, such as BitTorrent transfers, or a lot of home users, perhaps it would pay for itself in the aggravation eliminated. That is a value determination you will need to make for yourself. However, I strongly recommend that anyone who has to support a network, whether in the home or office, check out the Fing app, as I think it will quickly become a critical tool. I found it very helpful while working on a Wi-Fi extender column to monitor the virtual MAC addresses and confirm exactly what was happening on the network. I would not be surprised to learn that this tool helped you resolve problems that you didn’t even know you had.

References
1. Fing - Network Tools - Android Apps on Google Play. Google Play (2012) https://play.google.com/store/apps/details?id=com.overlook.android.fing&hl=en
2. App Store - Fing - Network Scanner. Apple App Store (2012). http://itunes.apple.com/us/app/fing-network-scanner/id430921107?mt=8
3. Download Fing. Overlook (2012). http://overlooksoft.com/download
4. Fing. Overlook http://www.overlooksoft.com/fing
5. Network Monitoring and Management Solutions. LookAtLAN http://lookatlan.com/oldindex.html
6. Domain Name System - Wikipedia. Wikipedia, the free encyclopedia (2012). http://en.wikipedia.org/wiki/Domain_Name_System
7. MAC address - Wikipedia. Wikipedia, the free encyclopedia (2012). http://en.wikipedia.org/wiki/Mac_address
8. Wake-on-LAN - Wikipedia. Wikipedia, the free encyclopedia (2012). http://en.wikipedia.org/wiki/Magic_packet

John Joyce is a laboratory informatics specialist based in Richmond, VA. He may be reached at editor@ScientificComputing.com.

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