| 1.3 |  | Security Framework and Policy |
| 1.3.2 |  | The security wheel in detail |

| Secure Secure the network by applying the security policy and implementing the following security solutions :

- Authentication - Give access to authorized users only. One example of this is using one-time passwords.
- Firewalls - Filter network traffic to allow only valid traffic and services.
- Virtual Private Networks (VPNs) - Hide traffic content to prevent unwanted disclosure to unauthorized or malicious individuals.
- Vulnerability patching - Apply fixes or measures to stop the exploitation of known vulnerabilities. This includes turning off services that are not needed on every system. The fewer services that are enabled, the harder it is for hackers to gain access.

Monitor
Monitoring security involves both active and passive methods of detecting security violations . The most commonly used active method is to audit host-level log files. Most operating systems include auditing functionality. System administrators for every host on the network must turn these on and take the time to check and interpret the log file entries.

Passive methods include using intrusion detection or IDS devices to automatically detect intrusion. This method requires only a small number of network security administrators for monitoring. These systems can detect security violations in real time and can be configured to automatically respond before an intruder does any damage.

An added benefit of network monitoring is the verification that the security devices implemented in Step 1 of the Security Wheel have been configured and are working properly.

Test
In the testing phase of the Security Wheel, the security of the network is proactively tested . Specifically, the functionality of the security solutions implemented in Step 1 and the system auditing and intrusion detection methods implemented in Step 2 must be assured. Vulnerability scanning tools such as SATAN, Nessus, or NMAP are useful for periodically testing the network security measures.

Improve
The improvement phase of the Security Wheel involves analyzing the data collected during the monitoring and testing phases, and developing and implementing improvement mechanisms that feed into the security policy and the securing phase in Step 1 . To keep a network as secure as possible, the cycle of the Security Wheel must be continually repeated, because new network vulnerabilities and risks are created every day.

With the information collected from the monitoring and testing phases, intrusion detection systems can be used to implement improvements to the security. The security policy should be adjusted as new security vulnerabilities and risks are discovered.