For security, you may want to limit the number of computers that can be connected to a given portion of the network. If there are too many, this may indicate that there are connections that don't belong there. Accordingly, the following command limits the number of MAC addresses that can be connected to a given interface (for example, in this case it limits the port to 10 addresses):
NTP (Network Time Protocol) synchronizes the time for time servers and clients. You can use it to synchronize your routers, switches, and access points. Synchronization also makes logs more useful, by ensuring that the timestamps are reliable.