at its very first step; the result of network scanning give an extensive information about the network, its OS, installed IDS/IPS and
firewalls, open ports and many other important information.
Selecting the right tool for the principle job is an art, and you are the artist. So select your hacking weapon wisely and if we talk about network scanning then we have Nmap (I think it does not need any introduction, right?). Undoubtedly Nmap is the smart tool that has an ability to get most of the job done but nmap is not the end, we have many other tools and they also have their own merits and demerits and one of them is ZMap.
What is ZMap?
ZMap is an open-source network scanner that enables researchers to easily perform Internet-wide network studies. With a single machine and a well provisioned network uplink, ZMap is capable of performing a complete scan of the IPv4 address space in under 5 minutes, approaching the theoretical limit of ten gigabit Ethernet.
port at the maximum rate possible. A more conservative configuration that will scan 10,000 random
addresses on port 80 at a maximum 10 Mbps can be run as follows:
$ zmap --bandwidth=10M --target-port=80 --max-targets=10000 --output-file=results.csv
$ zmap -B 10M -p 80 -n 10000 -o results.csv
subnets or CIDR blocks. For example, to scan only 10.0.0.0/8 and
192.168.0.0/16 on port 80, run:
zmap -p 80 -o results.csv 10.0.0.0/8 192.168.0.0/16
0% (1h51m left); send: 28777 562 Kp/s (560 Kp/s avg); recv: 1192 248 p/s (231 p/s avg); hits: 0.04% 0% (1h51m left); send: 34320 554 Kp/s (559 Kp/s avg); recv: 1442 249 p/s (234 p/s avg); hits: 0.04% 0% (1h50m left); send: 39676 535 Kp/s (555 Kp/s avg); recv: 1663 220 p/s (232 p/s avg); hits: 0.04% 0% (1h50m left); send: 45372 570 Kp/s (557 Kp/s avg); recv: 1890 226 p/s (232 p/s avg); hits: 0.04%
state of the scan and are of the following form: %-complete (est time
remaining); packets-sent curr-send-rate (avg-send-rate); recv:
packets-recv recv-rate (avg-recv-rate); hits: hit-rate.
network can support, you may want to experiment with different
scan rates or bandwidth limits to find the fastest rate that
your network can support before you see decreased results.