[Bp_ipv6] Request for clarification NAT v NAT

Marco Hogewoning marcoh at ripe.net
Fri Nov 27 05:10:48 EST 2015

> "
> NAT44 is not a transition technology, in the
> sense that deploying a CGN for translating IPv4 to IPv4 addresses will
> not get you one inch closer to deploying IPv6.
> However, NAT64 (a box that translates ipv6 packets into ipv4 packets) IS
> a transition technology."
>    But I think that if you have any concern with the current text we should try to add probably one more paragraph trying to make it clear. What does the rest of the group think?

Sounds about right…

How about:

Network Address Translation is an umbrella name for a variety of technologies. Where originally used to share a single public IPv4 address amongst multiple devices in network, which is common method in domestic Internet access as well as pubic access wifi networks. It also found use in enterprise networks to create more closed networks and reduce the administrative overhead involved when changing carriage providers, a step which require IP renumbering.

Lately these same technology is applied in a stacked fashion, commonly known as Large Scale or Carrier Grade NAT (CGN), where multiple levels of address sharing reduce the amount of IP addresses needed to operate access provider networks. While in short term such technologies can mitigate the effect if IPv4 address scarcity, the long term effects can have severe impact on network performance, traceability for law enforcement and the operating and expansion costs of networks. The widespread use of NAT will also harm the openness of the Internet, limiting future innovations that would rely on transparent any to any connectivity between machines at the IP level.

A different type of NAT, called NAT64, is used to translate between IPv4 and IPv6 networks, connecting the two incompatible protocols. This in particular allows users of IPv6 to connect to services that are still only available using the IPv4 protocol. While this translation again could introduce negative effects on traceability of overall network performance, it is widely regarded as an acceptable technology to aid in the deployment of IPv6. Especially in those cases where a single stack network setup, only using IPv6, is preferable over maintaining support for both IPv4 and IPv6 in an access network. Various 4G/LTE mobile access providers have chosen to deploy this technology as part of their IPv6 deployment.



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