scapy - python-based interactive packet manipulation program & library
ARPing - command-line network utility that has a functionality that is similar to the commonly used ping utility. This tool can identify whether a live host is on a local network at a given IP by supplying that IP address as an argument. This recipe will discuss how to use ARPing to scan for live hosts on a network. *
Burp Suite - integrated platform for performing security testing of web applications
ARP Ping - Arping is a util to find out it a specific IP address on the LAN is 'taken' and what MAC address owns it.