Make network security testing a routine and integral part of the system and network operations and administration. Organizations should conduct routine tests of systems and verify that systems have been configured correctly with the appropriate security mechanisms and policy. Routine testing prevents many types of incidents from occurring in the first place. The additional costs for performing this testing will be offset by the reduced costs in incident response. Test the most important systems first. In general, systems that should be tested first include those systems that are publicly accessible, that is,.