High CPU utilization problem

[mythldy]

When scanning 255 IPv4 addresses across ports 0-65535 with a packet sending rate of 30,000 packets per second, why does the CPU utilization exceed 75%? Are there any ways to reduce it?

[BulzN]

Hey @mythldy,

What you're seeing with CPU usage over 75% during high-speed scans (30k pps across 255 IPs and full port range) is actually expected now. Naabu v2.3.5 uses the CPU much more efficiently compared to earlier versions.

In fact, previous versions like v2.3.4 had the opposite problem: they barely used the CPU and scans took way longer. The latest release fixed that, so Naabu now fully leverages your system’s resources to run faster, especially during intensive scans like the one you're running.

If you want to reduce CPU usage a bit, here are a few ideas:

• Try lowering the packet rate (e.g., -rate 10000)

• Split your scan into smaller chunks, fewer IPs or narrower port ranges

• Run the scanner in container environments and limit the assigned CPU usage

• Or run the scan across multiple systems in parallel to spread the load

You can also check this related issue for more details on how performance has changed over the last few versions:

• The most stable version until now, but with some drawbacks and improvements needed #1374

Hope that helps