1.2.a (ii) Migrate parts of a network to IPv6

1.2.a [ii] Migrate parts of a network to IPv6

http://www.onlinetech.com/company/events/ipv4-to-ipv6-address-transition

IPv4-IPv6 Transition Methods

Due to the time that change takes, IETF has been working on specific provisions to allow a smooth transition from version 4 to version 6, and hardware and software interoperability solutions to let newer IPv6 devices access IPv4 hosts. A technique was included in IPv6 to allow administrators to embed IPv4 addresses within IPv6 addresses. Special methods are defined to handle interoperability, including:

• “Dual Stack” Devices: Routers and some other devices may be programmed with both IPv4 and IPv6 implementations to allow them to communicate with both types of hosts.
• IPv4/IPv6 Translation: “Dual stack” devices may be designed to accept requests from IPv6 hosts, convert them to IPv4 datagrams, send the datagrams to the IPv4 destination and then process the return datagrams similarly.
• IPv4 Tunneling of IPv6: IPv6 devices that don't have a path between them consisting entirely of IPv6-capable routers may be able to communicate by encapsulating IPv6 datagrams within IPv4. In essence, they would be using IPv6 on top of IPv4; two network layers. The encapsulated IPv4 datagrams would travel across conventional IPv4 routers.

Bear in mind that these solutions generally only address backward compatibility, to allow IPv6 devices to talk to IPv4 hardware. Forward compatibility between IPv4 and IPv6 is not possible because IPv4 hosts cannot communicate with IPv6 hosts—they lack the knowledge of how IPv6 works. 

There are both pre-deployment and deployment phases when it comes to migrating from IPv4 to IPv6. The specifics would really depend on the network that is being migrated however we can note down some broader areas that would need planning in each phase.

Pre-Deployment:

● Establish the network starting point

● Network assessment

● Defining early IPv6 security guidelines and requirements

Deployment:

● Transport considerations for integration

● Campus IPv6 migration options

● WAN IPv6 migration options

● Advanced IPv6 services options

Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Locations 1225-1237).  . Kindle Edition.