Cisco Certified Network Professional Practice Test 2026 – Your All-in-One Guide to Exam Success!

Dynamic ARP Inspection (DAI) is a security feature that helps mitigate ARP spoofing attacks by ensuring that only valid ARP requests and responses are processed. To enable DAI for a specific VLAN range, the correct command is to specify the VLAN or VLAN range you wish to activate this feature on. Using the command that includes "vlan vlan-range" allows the configuration to target multiple VLANs, offering a broader protection mechanism within those specified VLANs.

This ability to condition DAI to certain VLANs is crucial because it helps network administrators maintain tighter control over which segments of the network are safeguarded against ARP-related threats. By enabling DAI explicitly on a VLAN range, all ports within that VLAN or range will verify ARP packets, enhancing network integrity and security.

The other options do not specifically direct DAI settings to a VLAN range, making them less suitable for the intended configuration. Not specifying the VLAN would result in the feature not being applied as intended.