Network security policies are the methods that you use to protect your IT system by hardening all of your network devices and implementing traffic filtering at firewalls and routers. The implementation of these security rules requires the coordination of the settings on many devices, therefore, the whole process is termed network security policy management. For example, you can set up access control lists to block certain types of traffic from moving between zones of trust on your network. The creation of zones of trust is also part of your network security policy.