TABLE OF CONTENTS Migration is expected to be fairly complex. Initially, internetworking between the two environments will be critical. Existing IPv4-endpoints and/or nodes will need to run dual-stack nodes or convert to IPv6 systems. Fortunately the new protocol supports IPv4-compatible IPv6 addresses, which is an IPv6 address format that employs embedded IPv4 addresses. Tunneling, which we already described in passing, will play a major role in the beginning.
There are a number of requirements that are typically applicable to an organization wishing to introduce an IPv6 service [6NE200501]:
The existing IPv4 service should not be adversely disrupted (e.g., as it might be by router loading of encapsulating IPv6 in IPv4 for tunnels)
The IPv6 service should perform as well as the IPv4 service (e.g., at the IPv4 line rate and with similar network characteristics)
The service must be manageable and be able to be monitored (thus tools should be available for IPv6 as they are for IPv4)
The security of the network should not be compromised, due to the additional protocol itself or as a weakness of any transition mechanism used
An IPv6 address allocation plan must be drawn up
Well-known interworking mechanisms include the following [GIL200001].
Dual IP layer (also known as dual stack): A technique for providing complete support for both Internet protocols IPv4 and IPv6 in hosts and routers.
Configured tunneling of IPv6 over IPv4: Point-to-point tunnels made by encapsulating IPv6 packets within IPv4 headers to carry them over IPv4 routing infrastructures.
Automatic tunneling of IPv6 over IPv4:...
