libpcap: A system-independent interface for user-level packet capture.
libpcap: 
libpcap: libpcap provides a portable
libpcap: framework for low-level network monitoring.  Applications include
libpcap: network statistics collection, security monitoring, network debugging,
libpcap: etc.  Since almost every system vendor provides a different interface
libpcap: for packet capture, and since we've developed several tools that
libpcap: require this functionality, we've created this system-independent API
libpcap: to ease in porting and to alleviate the need for several
libpcap: system-dependent packet capture modules in each application.
libpcap: