Cisco Certified Network Associate (CCNA) Practice Exam

The command used to quickly check IP information of an interface is "show ip interface brief." This command provides a concise summary of the status and configuration of all interfaces, including their IP addresses, interface statuses (up or down), and whether they are administratively down. This makes it an efficient way to gather essential information about interfaces without delving into detailed operational data.

The other commands serve different purposes, which is why they are not suitable for quickly checking IP information. For instance, the "show ip interface INTERFACE" command gives detailed information about a specific interface, including configurations and operational status but can be too verbose for a quick check. "Show running-config" displays the full configuration of the device, which also contains more information than necessary for a quick IP check. Lastly, "show vlan" focuses on VLAN configurations and does not provide any pertinent information about IP addresses associated with interfaces. Thus, "show ip interface brief" is the best choice for a quick overview of IP information on interfaces.