300-420 Question 60
Single answerAn organization is migrating part of its network to IPv6 while maintaining connectivity with its existing IPv4 infrastructure. The network design requires a solution to enable communication between IPv4-only devices and IPv6-only devices. Which of the following options is the most appropriate solution for this scenario?
- A
Dual-stack configuration on all devices
- B
NAT64 with DNS64
- C
Tunneling IPv6 over IPv4
- D
ISATAP (Intra-Site Automatic Tunnel Addressing Protocol)
Show answer and explanation
Correct answer: B
Explanation
In scenarios where IPv4-only devices need to communicate with IPv6-only devices, NAT64 with DNS64 is the preferred solution. NAT64 translates IPv6 addresses into IPv4 addresses and vice versa, while DNS64 resolves DNS queries to facilitate communication. Other mechanisms, such as dual-stack or tunneling, do not provide this translation capability and are therefore unsuitable for this specific requirement.
- A. Incorrect.
Dual-stack allows devices to operate with both IPv4 and IPv6 simultaneously, but it does not facilitate direct communication between IPv4-only and IPv6-only devices. As such, it's not the correct solution in this specific scenario.
- B. Correct.
NAT64 with DNS64 is a translation mechanism that allows IPv6-only devices to communicate with IPv4-only devices. It translates IPv6 packets into IPv4 packets and vice versa, ensuring seamless communication. This makes it the most appropriate solution in this scenario.
- C. Incorrect.
Tunneling IPv6 over IPv4 is a method to transport IPv6 traffic across an IPv4 infrastructure, but it does not provide translation between IPv4 and IPv6. This option is not suitable for enabling communication between IPv4-only and IPv6-only devices.
- D. Incorrect.
ISATAP is a tunneling technology designed to help IPv6 traffic traverse IPv4 networks, but it is not a translation mechanism. It cannot enable direct communication between IPv4-only and IPv6-only devices.