Cyber Security… Port scanning with NMAP!

Andrea Pollastri
1 min readFeb 20, 2024

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If we are to defend, we first need to know what to defend. Asset Management often relies on Network Mapping to identify which systems are live on a network.

Asset management and knowing what you expose on the network, including which services are hosted is very important for anyone looking to defend their network.

Nmap is a network scanner created by Gordon Lyon (also known by his pseudonym Fyodor Vaskovich) and it’s used to discover hosts and services on a computer network by sending packets and analyzing the responses.

The first step to use is, is install it!

If you have a Mac, use Brew:

brew install nmap

Now you are ready to run a check:

 nmap TARGET

Where TARGET is a domain name (example.ltd) or an IP (123.123.123.123).

The response is a list of open ports (potentially vulnerable) related to host services. This situation could help any hacker to attack your system.

You can also add verbosity using:

 nmap TARGET -sV

Or extend the range of ports to check (this will require several minutes):

 nmap TARGET -p- -sV

Find more info here: https://nmap.org

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