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Which three approaches can be used while migrating from an IPv4 addressing scheme to an IPv6 scheme (choose three)
A. static mapping of IPv4 address to IPv6 addresses
B. configuring IPv4 tunnels between IPv6 islands
C. use DHCPv6 to map IPv4 addresses to IPv6 addresses
D. use proxying and translation (NAT-PT) to translate IPv6 packets into IPv4 packets
E. configure IPv6 directly
F. enable dual-stack routing
Answer: BDF
Explanation:
http://www.opus1.com/ipv6/howdoitransitiontoipv6.html
Connecting IPv6 islands with tunnels
An IPv6 island is a network made of IPv6 links directly connected by IPv6 routers. In the early days of IPv6 deployment, there are many IPv6 islands. IPv6 in IPv4 tunnels are used to connect those islands together. In each island, one (or more) dual stack routers are designated to encapsulate and decapsulate IPv6 packets within IPv4 packets. Different mechanisms have been developed to manage tunnels: automatic tunnels3, configured tunnels3, tunnel brokers3, 6over43, 6to43,…
http://www.petri.co.il/ipv6-transition.htm
Network Address Translation – Protocol Translation (NAT-PT) The NAT-PT method enables the ability to either statically or dynamically configure a translation of a IPv4 network address into an Application Layer Gateway (ALG) functionality that converts Domain Name System (DNS) the operation is very similar but includes a protocol translation function. NAT-PT also ties in an IPv6 network address and vice versa. For those familiar with more typically NAT implementations, mappings between protocols.
Dual Stack
The simplest approach when transitioning to IPv6 is to run IPv6 on all of the devices that are currently running IPv4. If this is something that is possible within the organizational network, it is very easy to implement.
However, for many organizations, IPv6 is not supported on all of the IPv4 devices; in these situations other methods must be considered.
