Scanning an IP address range

Very often, penetration testers and system administrators need to scan not a single machine but a range of hosts. Nmap supports IP address ranges in different formats, and it is essential that we know how to deal with them.

This recipe explains how to work with IP address ranges when scanning with Nmap.

How to do it...

Open your terminal and enter the following command:

# nmap -A -O 192.168.1.0-255

Alternatively you can use any of the following notations:

# nmap -A -O 192.168.1/24
# nmap -A -O 192.168.1.1 192.168.1.2 ... 192.168.1.254 192.168.1.255

How it works...

Nmap supports several target formats. The most common type is when we specify the target's IP or host, but it also supports the reading of targets from files, ranges, and we can even generate a list of random targets.

Any arguments that are not valid options are read as targets by Nmap. This means that we can tell Nmap to scan more than one range in a single command, as shown in the following command:

#...