Large scale scanning
In case of large existence of the target, large scale scanning is engaged. For example, with a global company, often a number of IP blocks exist as part of external internet facing. As mentioned earlier in Chapter 2, Open Source Intelligence and Passive Reconnaissance, attackers do not have time-limitations to scan, but penetration testers do. Pen testers can engage multiple tools to perform the activity; Masscan is one of the tools that would be engaged to scan large scale IP blocks to quickly analyze the target alive hosts. Masscan is installed in Kali by default. The biggest advantage of Masscan is randomization of hosts, speed, flexibility, and compatibility. The following screenshot provides a Class C scanning network within a few seconds to complete and identify the available ports and services running on the target hosts:

DHCP information
The Dynamic Host Configuration Protocol (DHCP) is a service that dynamically assigns an IP address to the hosts on the network...