If you’re a network administrator who is always on the go, you know it’s critical to have tools on your mobile device that will keep you apprised of the status of your network and machines. A number of mobile applications have been created for this very purpose. These are five free tools that I consider must haves for network admins who use Android phones. (Note: All of these apps are available in the Android Market.)

1: Ping!Up

Ping!Up is very basic, but it’s one of the first tools I grab when I know a connection is down is ping. The problem is you don’t always have a ping-ready tool with you; however, if you have an Android phone, you can have this simple to use ping tool.

To run a ping check, all you have to do is click the menu button, enter an address, and run the test. Figure A shows the results of a standard ping test run with Ping!UP.
Figure A

Ping!Up will also remember the addresses you have entered with a nice history. When you start to enter an address you’ve already ping’d, the address will appear in a drop-down.

2: HTTPing

HTTPing is very much like Ping, but this is for HTTP requests. The nice thing about this tool is that it will offer up error codes in case there is an issue.

As you can see in Figure B (as displayed on a Verizon Droid X), HTTPing is giving an error code of 301 on my request for http://www.techrepublic.com. The error code 301 indicates the address has been redirected (moved permanently to be specific). You might have to google your HTTP codes, but this tool will certainly provide what you need to know about the status of a URL.
Figure B

3: ConnectBot

If you have any need for secure shell connections, look no further than ConnectBot. This tool will have you easily connecting to your ssh servers, as well as importing encryption keys and even generating encryption keys. ConnectBot also allows you to copy and paste text into and out of the application. For anyone who administers a server or a desktop that can offer up a secure shell daemon, this is the way to go.

The biggest drawback to ConnectBot is that you cannot use pinch zoom to zoom into the text. As you can see in Figure C, the print is fairly small, and this is on an HTC EVO.
Figure C

If you hit the Menu button, you can create Port Forwards as well as resize the screen. You can make the screen larger by dropping the screen size, but by doing this, you will have to scroll the screen around to see the entire text depending upon how you size it.

4: Network Discovery

This incredibly handy tool allows you to find out what machine is attached to what IP address. After you install Network Discovery, you will need to be on a Wi-Fi network, and then you will have to download a database of NICs. When this is done you can click Discover and a list of all machines on that network will appear. A device will appear as an IP address and manufacturer (Figure D). You can also configure Network Discovery to resolve hostnames; this configuration will take more time, but it will provide you with useful information.
Figure D

If you click on a particular entry, you will see what ports the machine has open.

5: Port Scandroid

This tool can scan a single host and tell you very quickly what ports that machine has open. This is a great tool when you need to do a quick security audit on the go from your Android phone. Although Port Scandroid is very basic and it only does one thing (which it does quite well), this is the one port scanner you should use. The interface is clean and easy to figure out (Figure E).
Figure E

If you scroll all the way down, after the scan, you will get an at-a-glance of how many ports were scanned and how many are open.

More Android app recommendations on TechRepublic