PortListener

This quick and extremly dirty app listens for incoming TCP and/or UDP connections on a given port and displays the data received. Data can also be sent back. It took about 10 minutes to hash together and so has no error handling etc etc, and is pretty basic but its proved most useful.

I originally needed to check a program was making the DNS requestes it claimed to (even though this machine was offline, this program claimed its DNS requests were being answered!) so I set up a loop back interface, set my own IP as my DNS server and ran this on port 53 and saw the results. Its like an ultra naff packet sniffer/injector that only does TCP and UDP and is very basic. But, no additional drivers are reuired unlike most packet sniffers/injectors (WinPcap), I find it more compatible and for really basic checks its quick and easy so its a useful tool for me;

Screenshot:
 

Download the zip'ed up VB6 source HERE (includes binary)

(MSWINSCK.OCX may well be needed also, get it HERE)

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