Final answer:
Login throttling or account lockout, often known as watch mode, is a security feature where a router monitors failed login attempts over time to prevent unauthorized access. If too many failed attempts occur, the system may lock the user out.
Step-by-step explanation:
The term often used to describe when a router keeps count of the number of failed login attempts within an identified amount of time is login throttling or account lockout. This security feature, sometimes referred to as watch mode, is implemented to prevent unauthorized access by monitoring and limiting the rate at which login attempts can be made. If a certain threshold of failed attempts is reached, the account may be temporarily disabled or locked out to deter potential attackers from using automated tools to guess the password. In many systems, administrators can configure the sensitivity of this mechanism by setting the number of attempts and the time frame in which these attempts must occur to trigger the lockout.