Which command provides security on the console of a router?

To secure the console of a router, the command that is most appropriate is the one that configures a password specifically for console access. Setting a password for the console interface ensures that only authorized users can access the router’s command line through the console port, thus enhancing security.

In contrast, although specifying "enable secret" is an important security measure for privileged mode access, it does not directly apply to console access. The "line con 0" command is used to enter console line configuration but does not enforce any security by itself unless it is followed by the password command. Lastly, the access-list command allows certain types of traffic based on defined rules but does not provide direct security for the console interface.

Therefore, configuring a password specifically for the console face provides a primary level of security necessary to restrict unauthorized access.