In network security, which is more critical to monitor: successful logon attempts or failed logon attempts?

Monitoring failed logon attempts is critical in network security because such attempts can indicate potential unauthorized access attempts or malicious activities. A high number of failed logon attempts can signify that an attacker is trying to guess passwords or gain access to accounts, which could lead to serious security breaches if not addressed promptly.

By focusing on failed logon attempts, security professionals can identify patterns of suspicious behavior early and take preventive measures, such as locking accounts, deploying multi-factor authentication, or increasing monitoring around specific user accounts or services.

In contrast, while monitoring successful logon attempts may provide insight into normal user activity, it often lacks the immediate indication of potential security threats that failed attempts present. Therefore, prioritizing failed logon attempts allows for a proactive approach to mitigating risks associated with unauthorized access and maintaining the integrity of the network.