On 22 February 2017 at 06:21, Karsten Thomann
<karsten_thomann(_at_)linfre(_dot_)de> wrote:
Am Dienstag, 21. Februar 2017, 18:27:39 schrieb Job Snijders:
On Tue, Feb 21, 2017 at 09:49:32AM +0900, Lorenzo Colitti wrote:
On Tue, Feb 21, 2017 at 8:57 AM, Job Snijders <job(_at_)ntt(_dot_)net>
wrote:
<snip>
-------
OLD:
IPv6 unicast routing is based on prefixes of any valid length up to
128 [BCP198]. For example, [RFC6164] standardises 127 bit prefixes
on inter-router point-to-point links. However, the Interface ID of
all unicast addresses, except those that start with the binary value
000, is required to be 64 bits long. The rationale for the 64 bit
boundary in IPv6 addresses can be found in [RFC7421]
NEW:
IPv6 unicast routing is based on prefixes of any valid length up to
128 [BCP198]. When using [SLAAC], [ILNP], or [NPT66] the Interface ID
of unicast addresses is required to be 64 bits long. In other use
cases different prefix sizes may be required. For example [RFC6164]
standardises 127 bit prefixes on inter-router point-to-point links.
For most use cases, prefix lengths of 64 bits is RECOMMENDED, unless
there are operational reasons not to do so.
Satisfies my desired outcome of the text, but I would like to modify it:
IPv6 unicast routing is based on prefixes of any valid length up to
128 [BCP198]. When using [SLAAC], [ILNP], or [NPT66] the Interface ID
of unicast addresses is required to be 64 bits long. An exception is for
example [RFC6164] which standardises 127 bit prefixes on point-to-point
links. The RECOMMENDED prefix length is 64 bit,
It has to be stronger than a RECOMMENDED, because that implies it is
an arbitrary choice that won't have any protocol operational and
privacy or security impacts. That is not the case.
Have you and Job read,
"Analysis of the 64-bit Boundary in IPv6 Addressing
https://tools.ietf.org/html/rfc7421
?
(It has been referenced at some point in a version of this text
proposed I think.)
Regards,
Mark.