in reply to Net::Pcap does not work

The 04-loop.t test script for Net::Pcap can take a moment or two to complete - This script creates a Net::Pcap object which, using the loop method, listens for ten packets on the network interface returned by lookupdev method of this module and the underlying libpcap library. If your network is nascent, this process may take some time - It may be worthwhile to start an FTP download or alike in the background to generate the necessary network traffic for the loop method and underlying libpcap library to capture.

The loop method of the Net::Pcap library is described in my tutorial on this module here.