The Intertubes

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Over the history of IPv6, there have been many classful address models; TLA and NLA being outstanding examples. They have all been shown to be mistakes. The last is a magic boundary at /64. This document removes that last bit of useless magic.

Over the history of IPv6, there have been many classful address models; TLA and NLA being outstanding examples. They have all been shown to be mistakes. The last is a magic boundary at /64. This document removes that last bit of useless magic.

It is assumed that the reader understands IPv6, , IP Version 6 Addressing Architecture, see , and the proposed changes to , see .

To quote Lorenzo Colitti in the working group meeting at IETF 98, "Just because this is being elevated to full standard does not mean it can not be changed tomorrow." Tomorrow is here. Link prefixes of varied lengths, /127, /126, /124, /120, ... /64 have been successfully deployed for many years. Having the formal specification say otherwise risks potential mis-implementation by the naive, resulting in operational disasters.

To state it simply, IPv6 unicast routing is based on prefixes of any valid length up to 128 except for links where an Internet Standard such as Stateless Address Configuration , or Using 127-Bit IPv6 Prefixes on Inter-Router Links is in use.

For historical reasons, when a prefix is needed on a link, barring other considerations, a /64 is traditional.

This document has no known security impact.

This document has no IANA Considerations.

The original draft was by Randy Bush, who was immediately aided and abetted by Job Snijders, [ your name here ].

The authors wish to thank .