Which global command encrypts all passwords in the running configuration?

The `service password-encryption` command is a global configuration command that, when applied, automatically encrypts all currently unencrypted passwords (like console, VTY, and enable passwords set with `password` rather than `secret`) in the router's running and startup configuration files. It uses a reversible Type 7 encryption to prevent casual viewing of passwords.

`enable password-encryption` is not a valid command in Cisco IOS for encrypting all passwords.

`enable secret` is used to set the enable password with a strong, irreversible (MD5 or SHA256) hash, but it only applies to that specific password and does not encrypt other passwords in the configuration.

`password-encrypt` is not a valid command in Cisco IOS for encrypting passwords.