Question 319 of 367 from exam 200-301-CCNA: Implementing and Administering Cisco Solutions

Question 319 of 367 from exam 200-301-CCNA: Implementing and Administering Cisco Solutions


Where does a switch maintain DHCP snooping information?



A. B. C. D.


DHCP snooping is a security feature that prevents rogue DHCP servers from distributing incorrect or malicious IP configurations to clients. When enabled on a Cisco switch, DHCP snooping intercepts DHCP messages between clients and servers and verifies their legitimacy based on preconfigured policies.

The DHCP snooping information is stored in a binding database. The binding database is a table that maps the MAC addresses of DHCP clients to their associated IP addresses and other DHCP-related information, such as lease duration and VLAN ID. This database is maintained by the switch and is used to validate DHCP messages and ensure that the correct IP configurations are delivered to the appropriate clients.

The binding database is created and updated dynamically as DHCP messages are received and processed by the switch. When a DHCP client sends a request message, the switch intercepts the message and checks the binding database to verify if the client is authorized to receive an IP address. If the client is authorized, the switch creates a new binding entry in the database and forwards the request message to the DHCP server. When the server responds with an offer message, the switch checks the binding database again to ensure that the offer is valid before forwarding it to the client.

In addition to the binding database, the switch also maintains a CAM table, a frame forwarding database, and a MAC address table. The CAM table is used to store the MAC addresses of connected devices and their associated switch ports. The frame forwarding database is used to store information about how to forward frames to specific destinations based on their MAC addresses. The MAC address table is used to map MAC addresses to VLAN IDs for VLAN-based forwarding.

However, DHCP snooping information is not stored in the CAM table, frame forwarding database, or MAC address table. These tables are used for different purposes related to forwarding and switching frames, but they do not contain information specific to DHCP snooping.