Because AH transport mode cannot alter the original IP header, it is generally used in which VPN architecture?

Because AH transport mode cannot alter the original IP header, it is generally used in which VPN architecture?

• A. Gateway-to-gateway
• B. Host-to-gateway
• C. Host-to-host
• D. Gateway-to-host

Answer: (C)

The correct answer is host-to-host. In the context of VPN architecture, AH (Authentication Header) transport mode is used primarily in scenarios where the integrity and authenticity of the IP packets are paramount, while the original IP header remains unchanged. This is particularly relevant in host-to-host configurations where two end devices (hosts) are communicating directly over the Internet or another network. In host-to-host VPNs, each host can authenticate the IP headers and the payload of the data being transmitted, without needing to modify the IP header itself. This maintains the original source and destination address in the packet, ensuring that both hosts can verify the integrity of the traffic. Because AH transport mode provides authentication at the IP level without encapsulating the original packet (as transport mode does not add new headers), it is well-suited for point-to-point VPNs between individual machines. Other VPN architectures may utilize different modes for efficiency or functionality depending on their specific requirements. For instance, gateway-to-gateway might be more suited for scenarios requiring tunneling, as it often involves encapsulating entire packets for traffic between networks rather than just securing the transported packets. Similarly, host-to-gateway or gateway-to-host configurations might have different approaches to addressing encryption, security, and routing functionalities based on

The correct answer is host-to-host. In the context of VPN architecture, AH (Authentication Header) transport mode is used primarily in scenarios where the integrity and authenticity of the IP packets are paramount, while the original IP header remains unchanged. This is particularly relevant in host-to-host configurations where two end devices (hosts) are communicating directly over the Internet or another network.

In host-to-host VPNs, each host can authenticate the IP headers and the payload of the data being transmitted, without needing to modify the IP header itself. This maintains the original source and destination address in the packet, ensuring that both hosts can verify the integrity of the traffic. Because AH transport mode provides authentication at the IP level without encapsulating the original packet (as transport mode does not add new headers), it is well-suited for point-to-point VPNs between individual machines.

Other VPN architectures may utilize different modes for efficiency or functionality depending on their specific requirements. For instance, gateway-to-gateway might be more suited for scenarios requiring tunneling, as it often involves encapsulating entire packets for traffic between networks rather than just securing the transported packets. Similarly, host-to-gateway or gateway-to-host configurations might have different approaches to addressing encryption, security, and routing functionalities based on