On 8/11/12 10:13 AM, Donald Eastlake wrote:
One problem with excessively large fields, including variable length
addresses with a high maximum length, is that the next time someone
wants to encode some additional information, they just tuck it inside
that field in some quasi-proprietary way, instead of going to the
trouble of actually adding a field. Witness X.509 Certificate "serial
numbers", which are arbitrary precision integers, but which frequently
are used for a variety of information, all BER encoded...
given various semantic uses of bits within ipv6 addresses that have been
proposed or which are used informally even with only 128 bits it's
important to make this distinction. a freely extensible bit field will
end up with all sorts of garbage in it, that at best is only signficant
in one context, and at worse is significant in different fashions in
different contexts.
instead of having an locator-id you have a
locator-qos-mpls-subscriberid-streetaddress-latlong-id
Thanks,
Donald
=============================
Donald E. Eastlake 3rd +1-508-333-2270 (cell)
155 Beaver Street, Milford, MA 01757 USA
d3e3e3@xxxxxxxxx
On Fri, Aug 10, 2012 at 1:35 PM, David Conrad <drc@xxxxxxxxxxxxxxx> wrote:
On Aug 10, 2012, at 10:22 AM, "Andrew G. Malis" <agmalis@xxxxxxxxx> wrote:
Another alternative is self-describing variable-length addresses,
again do it once and we'll never have to worry about it again.
Heretic! That's OSI speak! Why do you hate the Internet you ISO/ITU lackey?!?
</flashback>
Yeah, variable-length addresses would have been nice. There was even working code. Maybe next IPng.
Regards,
-drc