nanog mailing list archives

Re: IPv6 Netowrk Device Numbering BP


From: Zachary Giles <zgiles () gmail com>
Date: Thu, 1 Nov 2012 08:37:19 -0400

Though 2001:abcd::192:168:10:10 was written in a format with both :
and . , I think would could take the concept mentioned above and
extend it either by making it
2001:abcd::C0:A8:0A:0A
or
2001:abcd::C0A8:0A0A

Doing the latter wastes less space and let's the host use the upper
32bits of the host portion for vhosts.
Ex: 2001:abcd::1:C0A8:0A0A

Should be easy enough as something like pxelinux already squishes your
v4 address down to do file searching on tftp servers.
Ex: /mybootdir/pxelinux.cfg/C000025B for 192.0.2.91


I personally have for this "use the last 32bits of the v6 address for
the v4 dual stack address" trick and was happy with it. Still fits
with the concept of "give each host a /64"


On Thu, Nov 1, 2012 at 8:20 AM, Masataka Ohta
<mohta () necom830 hpcl titech ac jp> wrote:
Eugeniu Patrascu wrote:

You can say it's a IPv4 thinking model, but it's easier to remember
that if the fileserver it's at 192.168.10.10 then it's IPv6
counterpart address would be 2001:abcd::192:168:10:10 (each subnet
being a /64)

That is a clever idea except that it can not always follow
modified EUI-64 format aof rfc4291.

We should better introduce partially decimal format for
IPv6 addresses or, better, avoid IPv6 entirely.

                                                Masataka Ohta




Another option would be to do both. Assign a fixed address and also
let it chose EUI-64. However, I see that leading to confusion. Not
sure what good it would do.

Is there anything like a standard, best practice for this (yet)?
What are other people doing and their reasons? Anyone have operational
experience with what works and what does not (and the "what does
not" is probably really of more interest)?

Letting the host choose it's own IP can be very tricky and has
operational hurdles along the way as it's not that easy to copy
configurations across devices during upgrades and maintenance swap
outs.








-- 
Zach Giles
zgiles () gmail com


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