Description: Deny by default is a security policy used in firewalls and access control systems that states that all network traffic is blocked unless explicitly allowed. This strategy is based on the principle that it is safer to assume that any unauthorized connection attempt is potentially harmful. By implementing this policy, network administrators can significantly reduce the risk of cyberattacks, as only traffic that has been previously authorized is permitted. This methodology contrasts with the ‘allow by default’ policy, where all traffic is accepted unless stated otherwise. Deny by default is especially useful in environments where security is critical, such as in corporate or government networks, where exposure to external threats must be minimized. Additionally, this policy encourages a more careful review of access rules, as each exception must be justified and documented, contributing to better management of network security.
