Virtual Local Area Networks (VLANs)

Correct Answer: DHCP relay

The best answer is DHCP relay. In a network with multiple VLANs, a DHCP server may not be directly connected to each VLAN. To efficiently distribute IP addresses to devices in different VLANs, a DHCP relay agent can be configured on a router or Layer 3 switch. The DHCP relay forwards DHCP requests from clients in different VLANs to the central DHCP server and relays the DHCP responses back to the clients. DHCP snooping is a security feature that prevents unauthorized DHCP servers from distributing IP addresses, but it does not help with distributing addresses across VLANs. DHCP reservation is used to assign a specific IP address to a device based on its MAC address, which is not related to distributing addresses across VLANs. DHCP failover provides redundancy between two DHCP servers, but does not address the distribution of IP addresses to different VLANs.

Correct Answer: Create a separate guest VLAN; restrict access to internal VLANs

Creating a separate guest VLAN and restricting access to internal VLANs is the best configuration for providing visitors with internet access without compromising the security of internal network resources. This setup isolates the guest traffic from the internal network, preventing unauthorized access to sensitive data and systems. The other options, such as adding guests to the default or existing VLANs, or allowing access to all internal VLANs from the guest VLAN, would expose the internal network to potential security risks.

Correct Answer: Implement a router-on-a-stick configuration

Implementing a router-on-a-stick configuration is the best solution in this scenario. This setup allows a single router interface to route traffic between multiple VLANs, enabling the printer to be shared across the two departments while maintaining network segmentation. The router acts as a central point, connecting the VLANs and facilitating inter-VLAN communication for the printer. Configuring separate subnets for the two departments is not sufficient on its own, as it does not address the need for inter-VLAN communication between the departments and the shared printer. Using a layer 2 switch to connect the printer would not enable communication between the separate VLANs, as layer 2 switches operate within a single broadcast domain and cannot route traffic between VLANs. Connecting the printer to both VLANs directly is not a viable solution, as it would require the printer to have multiple network interfaces and would not provide proper network segmentation and security.