Discussion:

This requirement applies regardless of whether the logon occurs via a local or network connection. Due to the potential for denial of service, automatic lockouts initiated by systems are, in most cases, temporary and automatically release after a predetermined period established by the organization (i.e., a delay algorithm). If a delay algorithm is selected, organizations may employ different algorithms for different system components based on the capabilities of the respective components. Responses to unsuccessful logon attempts may be implemented at the operating system and application levels.

Determining Statements (NIST SP 800-171Ar2)

Upon assessment, assessors must determine if-

3.1.8[a] the means of limiting unsuccessful logon attempts is defined.
3.1.8[b] the defined means of limiting unsuccessful logon attempts is implemented.

Assessors are instructed to-

Examine: [SELECT FROM: Access control policy; procedures addressing unsuccessful logon attempts; system security plan; system design documentation; system configuration settings and associated documentation; system audit logs and records; other relevant documents or records].

Interview: [SELECT FROM: Personnel with information security responsibilities; system developers; system or network administrators].

Test: [SELECT FROM: Mechanisms implementing access control policy for unsuccessful logon attempts].