6.3.e Describe IPv6 network address translation

6.3.e [i] NAT64

Network Address Translation IPv6 to IPv4, or NAT64, technology facilitates communication between IPv6-only and IPv4-only hosts and networks (whether in a transit, an access, or an edge network). This solution allows both enterprises and ISPs to accelerate IPv6 adoption while simultaneously handling IPv4 address depletion . The DNS64 and NAT64 functions are completely separated, which is essential to the superiority of NAT64 over NAT-PT.

All viable translation scenarios are supported by NAT64, and therefore NAT64 is becoming the most sought translation technology.

AFT using NAT64 technology can be achieved by either stateless or stateful means:

● Stateless NAT64 , defined in RFC 6145, is a translation mechanism for algorithmically mapping IPv6 addresses to IPv4 addresses, and IPv4 addresses to IPv6 addresses . Like NAT44, it does not maintain any bindings or session state while performing translation, and it supports both IPv6-initiated and IPv4-initiated communications.

● Stateful NAT64, defined in RFC 6146, is a stateful translation mechanism for translating IPv6 addresses to IPv4 addresses, and IPv4 addresses to IPv6 addresses. Like NAT44, it is called stateful because it creates or modifies bindings or session state while performing translation. It supports both IPv6-initiated and IPv4-initiated communications using static or manual mappings.

Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Locations 6025-6028).  . Kindle Edition.

http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/enterprise-ipv6-solution/white_paper_c11-676278.html