Zmap

Overview:
ZMap is a fast network scanner designed for Internet-wide network surveys. On a typical desktop computer with a gigabit Ethernet connection, ZMap is capable scanning the entire public IPv4 address space in under 45 minutes. With a 10gigE connection and PF_RING, ZMap can scan the IPv4 address space in under 5 minutes.

While previous network tools have been designed to scan small network segments, ZMap is specifically architected to scan the entire address space. It is built in a modular manner in order to allow incorporation with other network survey tools. ZMap operates on GNU/Linux and supports TCP SYN and ICMP echo request scanning out of the box.