Q: I get this exception when I try to access any methods from org.jnetpcap.winpcap package.

A: The exception is telling you that on this particular platform the winpcap extension is not available and can not be used.

WinPcap native library is a windows implementation of libpcap library. It supports all of the libpcap functions and adds several new capabilities but only on windows platforms. jNetPcap API provides WinPcap extention only on windows platform.

In order to avoid having this error thrown, the user must check if WinPcap extension is supported on this particular platform at runtime. To check for support use WinPcap.isSupported():boolean method which will return a boolean true if it is supported, otherwise false. This method never throws an exception and needs to be used before your code relies on any features within that winpcap package.