Clicking on the CentOS Network Notification Tool displays critical information about the system as well as a list of available updates. If you are using an older version of the CentOS Update Agent, the dialog box displays a message similar to Figure 4 recommending that you upgrade to the latest version. If you not running the latest available kernel, the Critical Information tab displays a warning.
The Available Updates tab displays a list of available package updates, including the installed version number and the available version number.