PortKnock Lite

This is a very simple port knocker for the iPhone. You *must* have a port knock daemon running on your server for this application to be useful.

Please note, if you do not already know what port knocking is, this app will likely not be useful to you. But if you do know, please leave me some comments, pro or con so I can gauge how you folks are using the app.

-- Use Cases --
This app is ideal if youre on a WiFi network but dont have a port knocker on the available computers. If youre sitting behind a NAT, the iPhone/iPod Touch will have the same IP as any of the other computers on your network.

This is also great to use with TouchTerm or any other ssh or telnet software for the iPhone.

Just give it the hostname and a list of ports, and whether you want it to send TCP or UDP packets.

-- Additional Info --
If youre in need of a knock server, I personally use Judd Vinets knock daemon for linux. Its quite easy to use: http://www.zeroflux.org/projects/knock

You can find of information and a nice list of other knock clients and servers over at http://www.portknocking.org/

-- Brief Description of Port Knocking for the Layman --
Port Knocking is a technique to secure services behind a firewall until a specific knock sequence is given. This is not to be confused with port scanning (a network management tool for discovering open services on a system).

Imagine you left your kids at home alone. You dont want them to open the door for strangers. And when a stranger comes knocking, you dont even want them to come to the door, because you dont want them to know your kids are there. But, when you or other family members come, you might want them to open the door for you. So you teach them to listen for a certain rattat-tat-tat or special knock that only you and your family know.

This is the same concept you can apply to your servers. If you run a knock daemon on your server, this app then lets you send the special knock to it.

A more technical description of port knocking can be found on Wikipedia:
http://en.wikipedia.org/wiki/Port_knocking