Packet generator/sniffer and network scanner/discovery

 Scapy is a powerful interactive packet manipulation tool, packet
 generator, network scanner, network discovery, packet sniffer, etc. It
 can for the moment replace hping, 85% of nmap, arpspoof, arp-sk, arping,
 tcpdump, tethereal, p0f, ....
 .
 In scapy you define a set of packets, then it sends them, receives
 answers, matches requests with answers and returns a list of packet couples
 (request, answer) and a list of unmatched packets. This has the big advantage
 over tools like nmap or hping that an answer is not reduced to
 (open/closed/filtered), but is the whole packet.