Cisco Certified Network Associate (CCNA) Practice Exam

What command would you use to check whether an ACL is attached to an interface?

1. #show ip interface

2. #show ipv6 interface

3. #display acl status

4. #check acl interface

The correct answer is: #show ipv6 interface

The command to check whether an Access Control List (ACL) is attached to an interface is indeed the one that begins with "show ip interface." When you use this command, it provides detailed information about the IP configuration of the interfaces on a router or switch. This includes details about any configured access lists. Specifically, the output will indicate if an ACL is applied to the inbound or outbound traffic on an interface, showing which ACL is in use if one is present. This is crucial for network management, as it allows administrators to verify security policies enforced at the interface level. While the command related to "ipv6 interface" could show similar details for IPv6 interfaces, it does not represent the most general form to check ACLs, particularly for IPv4 traffic, which is commonly encountered. Other options such as "display acl status" and "check acl interface" are not standard Cisco commands. Consequently, they would not yield the necessary information regarding ACLs assigned to interfaces.