Follow these steps to display open, closed and blocked ports using nmap.
- In the Target field at the upper left-hand corner of Nmap, type the IP Address of your subnet and select Scan. Following are some common IP subnets:
- Select the Ports / Hosts tab to view open, closed and blocked ports.
In this example, we have a network with about 15 hosts. We can highlight an IP address to view the state of the ports on a particular host.
The -p (ports) option can be appended to the command to only search for a certain port in question.
nmap -p 80,443 -O sS 192.168.0.0/24