262 Technique 37: Evaluating Your Network Security with Nessus

You can enter multiple machines in the Target(s) field by separating the host names (or IP addresses) with a , (comma). Click the Start the Scan button, and a scan of all the systems displays on the desktop.

Reading the grim results

At first glance, the scan report looks pretty good; in fact, it looks empty (see Figure 37-12). Just wait until you start exploring.

• Figure 37-12: The scan results.

The good news is, the reports will tell you what to do about any security breaches Nessus finds. The bad news, well, bear with us. Here’s how to delve into the report:

1. Highlight the subnet for your system in the

Subnet frame.

The individual machines that you’ve included in the scan are listed below, in the Host frame.

2. To see itemized information about what the scan found for each machine, highlight the machine address.

A list of the ports found open in the scan appears in the Port frame, as shown in Figure 37-13.

• Figure 37-13: The ports that Nessus explored.

The icons to the left of the ports tell you what Nessus found when connecting to those ports. A yellow triangle with a ! in it indicates a port you should be concerned about.

3. Highlight the port name, and the Security

Warning icon displays in the Severity frame, as shown in Figure 37-14. Highlight the security warning to view detailed information about the scan results in the bottom frame of the window.

A red stop sign with a line through it indicates a security hole.

A triangle with an exclamation point indicates a security warning.

A light bulb indicates a security note (just a bit of trivia you might find interesting).

4.Highlight one of the ports with an icon next to it to open the details in the Severity frame.

You may find that a given port sponsors more than one level of offense.