Time-Based ACLs, as its name implies is one type of ACL that allows access based on the time of day and week. This type of ACL works best with the use of NTP (Network Time Protocol) synchronization instead of using Router system clock. Reflexive ACLs filter traffic based on upper layer session, which allows outbound traffic while limiting inbound traffic. Refer to the link provided to see an example configuration of Time-Based ACL. Lock and Key ACL (Dynamic ACL) is dependent on the use of Telnet, authentication, and extended ACL. In a Dynamic ACL, users are blocked until they establish a Telnet connection to the router and get authenticated. - - - - - - - - As of Dec-2015, the CCNA objectives for ACLs is for: Standard, Extended, Named, & use of the : "log" option. {time-based ACL's are currently listed as an Exam-Topic for CCNP-Level Routing Cert} - - - - - - note most simulators, and even Cisco PackeTracer don't support the creation of Time-Based ACL, fun-note: you can use the command: "show time range" to see your configured "Time-Ranges, pretty much like you would see with: "show access-list"