Configure High Performance Mode

The following steps are required to operate Tenable Nessus Network Monitor in High Performance mode. Alternatively, a user with administrative privileges can enable High Performance mode via the UI.

Tenable Nessus Network Monitor uses multiple cores to process packets received from monitored interfaces. These are known as worker cores. The default number of worker cores is 8. This number can be changed using the configuration parameter Number Of Worker Cores.

Note: Tenable Nessus Network Monitor supports a maximum number of 16 cores.

Note: If you set the Number Of Worker Cores parameter to 0, Tenable Nessus Network Monitor automatically changes the value to the minimum number of worker cores needed to run Tenable Nessus Network Monitor in High Performance mode.

For example, suppose you have 20 available logical cores. Four of those cores are used by the system for internal processing and the kernel. If you want to use the 16 available cores for Tenable Nessus Network Monitor, then you may change the value for the parameter Number Of Worker Cores to 16.

Before you begin:

• Ensure you have a High Performance Activation Code so you can run Tenable Nessus Network Monitor in High Performance mode.

• If you are running Red Hat Enterprise Linux, ensure Secure Boot mode is disabled, as described in Disable Secure Boot for Tenable Nessus Network Monitor High Performance Mode.

To configure High Performance Mode:

1. Stop Tenable Nessus Network Monitor with the following command:

   # service nnm stop

2. Enable High Performance mode with the following command:

   /opt/nnm/bin/nnm --config "Enable High Performance Mode" "1"

3. Confirm that the management network interface is different from the monitoring network interface that you configured initially.

   Note: If the configured monitored interface has bound IPv4 addresses, you cannot complete the Quick Setup Wizard to configure Tenable Nessus Network Monitor because no usable NICs appear in the Monitored Network Interfaces list.

4. Start Tenable Nessus Network Monitor with the following command:

   # service nnm start