The Juniper EX switch must be configured to enforce the limit of three consecutive invalid logon attempts for any given user, after which time it must block any login attempt for that user for 15 minutes.

By limiting the number of failed login attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Introducing a lockout period significantly increases the time required for each brute-force attack and increases the likelihood that security personnel will identify (and can respond to) an ongoing attack and/or that the authorized owner will recognize and report the unauthorized activity.