How to Scan a Host When Ping Is Blocked by a Firewall | Nmap Tutorial

Hi everyone, Horbio this side, and welcome back to another cybersecurity video.

Today, we’re going to talk about an interesting situation that you can face during network reconnaissance.

Imagine you’re performing an authorized security assessment, and you have a target IP address, for example:

10.x.x.x

The first thing you might want to know is:

“Is this target machine alive?”

So, I started with a simple ping:

ping 10.x.x.x

But I didn’t receive any response.

I tried it several times, but still, there was no reply.

At this point, you might think:

“Maybe the machine is offline.”

But that’s not necessarily true.

A host can be online while simply refusing to respond to ICMP echo requests.

So instead of immediately assuming that the target was down, I decided to perform a TCP-based scan using Nmap.

I ran:

nmap -sS 10.x.x.x

And this time, Nmap was able to identify open TCP ports on the target.