In addition to the IPv4-embedded IPv6 unicast addresses, a series of other tools and techniques can be used to facilitate a migration. These tools are native to the IPv6 protocol suite and include the following:
Product support for running dual protocol stacks (IPv4 and IPv6)
IPv6 tunneling through IPv4 core networks
Translation gateways (Network Address Translation-Protocol Translation [NAT-PT])
Each of these is worth exploring in a bit more detail, although NAT-PT is not yet supported as of Cisco IOS Software Release 12.2(2)T.
A classic technique for migration is to run in a parallel environment. In other words, you establish the new environment in parallel with the old. Both coexist long enough for a ...