Cisco CCNA mock exam questions sample test – Question 180

.You are the network administrator for your company. You want to upgrade the network, which is currently running on IPv4, to a fully functional IPv6 network. During the transition, you
want to ensure that hosts capable only of IPv6 can communicate with hosts capable only of IPv4 on the network.
Which solution should you implement to accomplish the task in this scenario?

A. IPv6 over IPv4 tunnels
B. IPv6 over dedicated Wide Area Network (WAN) links
C. Dual-Stack Backbones
D. Protocol translation


Correct Answer: D

Explanation:
The protocol translation deployment model should be used to accomplish the task in this scenario. It is the only offered solution that does not require at least one end of the
communication solution to support both IPv6 and IPv4.
The following deployment models are available for IPv4 to IPv6 migration:
IPv6 over IPv4 tunnels: IPv6 traffic is encapsulated into IPv4 packets. Then these packets are transferred over IPv4 WAN. This model eliminates the need to create separate
circuits to connect to the IPv6 networks. This model increases protocol overhead because of the IPv6 headers and requires the edge router at each end be capable of both
protocols.
Protocol translation: A method allowing an IPv6 host to communicate with an IPv4 host. This is accomplished with the help of Network Address Translation – Protocol Translation
(NAT-PT) used to configure translation between IPv6 and IPv4 hosts. NAT-PT allows communication between IPv6 hosts and applications, and native IPv4 hosts and applications.
IPv6 over dedicated WAN links: A new deployment of IPv6 is created. In this model, IPv6 hierarchy, addressing, and protocols are used by all nodes. However, this model involves
cost for creating IPv6 WAN circuits. This solution is not designed for LAN translation but rather communication over WAN links.
Dual-Stack Backbones: A hybrid model in which backbone routers have dual-stack functionality, which enables them to route both IPv4 and IPv6 packets. It is suitable for an
enterprise that uses both IPv4 and IPv6 applications. Running IPv6 and IPv4 together in a network is known as dual-stack routing.
Objective:
Network Fundamentals
Sub-Objective:
Identify the appropriate IPv6 addressing scheme to satisfy addressing requirements in a LAN/WAN environment
References:
Cisco > Products and Services > Security > Cisco IOS Network Address Translation (NAT) > Data Sheets and Literature > White Papers > Network Address Translator-Protocol
Translator