Tenable Security Center is a vulnerability management platform, built on Nessus technology, which gathers and evaluates vulnerability data across multiple Nessus® scanners distributed across your enterprise. Utilizing advanced analytics, customizable dashboards/reports and workflows to identify weaknesses on your network. Tenable Core is the virtual appliance platform we use as the base for many of our applications. Tenable Core is a customized version of Oracle Linux 8. It has these major features:

Security-Enhanced Linux Enabled (see https://selinuxproject.org/)
Pre-configured using CIS Level 1 standards (see (https://docs.tenable.com/tenablecore/SecurityCenter/Content/TenableCore/DefaultSecurityConfigurations.htm for specific implementation)
A GUI for configuration of a number of application and OS features. bundle up to 500 IP bands