To view all IP ACLs on the router, which command would you use?

The command to view all IP Access Control Lists (ACLs) on a Cisco router is "show ip access-lists." This command provides a comprehensive display of all the configured IP ACLs, including the ACL name and the individual entries that specify the rules for filtering traffic.

Using this command is vital for network administrators as it allows them to monitor and analyze the current access control configurations. It helps in verifying whether the ACLs are set up correctly and behaving as intended to enforce security policies.

The other options do not provide the correct syntax specifically for displaying IP ACLs. For example, "show access-lists" is a more general command that might not specify IP-based ACLs, while "list ip access-lists" and "access-list view ip" are not recognized commands in Cisco IOS, which is why they wouldn't be effective in retrieving the desired information.