Cisco Certified Internetwork Expert (CCIE) Practice Test

What must be configured for an access device to utilize IP device tracking?

1. Dynamic ARP Inspection must be enabled

2. DHCP snooping must be configured

3. Port Security must be configured

4. Router advertisements must be enabled

The correct answer is: DHCP snooping must be configured

To enable IP device tracking on an access device, DHCP snooping must indeed be configured. DHCP snooping acts as a security feature that helps to prevent rogue DHCP servers from distributing IP addresses to clients on the network. This feature tracks the binding of IP addresses to MAC addresses when a DHCP server leases an IP address to a device. When DHCP snooping is enabled, the access device maintains a database of these bindings, which is crucial for IP device tracking. This database is what allows the network to keep consistent records of which devices are currently connected and to which IP addresses they have been assigned. By knowing the relationship between IP addresses and corresponding MAC addresses, the network can effectively manage and monitor IP address usage, enhancing security and operational efficiency. While other options may provide valuable features for network security or operations, they do not directly contribute to the functionality of IP device tracking. For example, dynamic ARP inspection helps prevent ARP spoofing, while port security limits the number of MAC addresses on a switch port, but they do not provide the necessary binding information that DHCP snooping does. Router advertisements are related to IPv6 address autoconfiguration and do not play a role in IP device tracking for IPv4 addresses.