#!/bin/bash # Run this on your internet-connected proxy /opt/nessus/sbin/nessuscli fetch --all --directory /var/nessus_offline_mirror
Locate the Activation Code row and click the to modify settings. Switch the drop-down selector from Online to Offline .
Offline registration is not a one-time task. Nessus relies on daily plugin updates to detect new security flaws. nessus offline registration hot
| Requirement | Details | |-------------|---------| | Nessus version | 8.x, 9.x, 10.x (the process is similar) | | Activation code | Nessus Professional, Nessus Expert, or Tenable.io (some tiers support offline) | | Offline host | Linux, Windows, or macOS without internet | | Online machine | Any OS with browser & internet | | USB / secure transfer | To move files between machines |
The primary driver for offline registration is the existence of air-gapped networks. In sectors such as government defense, critical infrastructure, and high-security finance, networks are deliberately isolated from the public internet to prevent unauthorized data exfiltration and remote attacks. For these organizations, the standard Nessus activation method—which requires the scanner to "phone home" to Tenable’s license servers—is impossible. The inability to register the tool renders it useless, creating a Catch-22 where the tool designed to find vulnerabilities cannot be activated because of the very security measures it is meant to support. Therefore, mastering the offline registration process is essential for maintaining the security posture of these isolated environments. Nessus relies on daily plugin updates to detect
Be aware that Tenable Nessus Pro license prices saw an increase effective March 2, 2026, which may affect renewal strategies for offline environments.
: The completely isolated, internet-free machine hosting the Nessus instance. Share public link
I can provide customized CLI scripts or precise config steps tailored to your environment. Share public link