Linux – How to scan using nmap and Zenmap all hostnames that begin with a particular string

nmap versions lower than 5.30BETA1:

nmap -sP 192.168.1.*

newer nmap versions:

nmap -sn 192.168.1.*

This gives me hostnames along with IP adresses, and only pings the hosts to discover them. This will only give you the hostnames if you run it as root.

EDIT: As of Nmap 5.30BETA1 [2010-03-29] -sP has been replaced with -sn as the preferred way to do ping scans, while skipping port scanning, just like the comments indicate:

Previously the -PN and -sP options were recommended. This establishes a more regular syntax for some options that disable phases of a scan:

• -n no reverse DNS
• -Pn no host discovery
• -sn no port scan

Even though 10.0.0.0 is defined as a Class-A network, you can still define smaller networks inside it.

So 10.0.0.0/24 is used to define a smaller network ranging from 10.0.0.0 to 10.0.0.255. As example, /23 could also have been used to define a network ranging form 10.0.0.0 to 10.0.1.255, etc.

I would suggest you look into the CIDR calculator at the following URL (http://www.subnet-calculator.com/cidr.php)

As a side note, in your command, you are not asking NMAP to ping an IP... you are asking that he scan a defined range. You could also point it toward a single IP, but NMAP will most likely translate it as $ip/32.