I quite like the pcap library, and in turn the Net::Pcap module. I thus thought it pertinent to add that Net::RawIP also incorporates an interface to pcap, specifically Net::RawIP::libpcap - This interface provides all the same functions as Net::Pcap and provides a capture mechanism to pair with Net::RawIP's packet building methods.

 

perl -le 'print+unpack("N",pack("B32","00000000000000000000001000010001"))'