FUS for IP space fragmentation (Re: fair warning: less than 1000 days left to IPv4 exhaustion)

[Edward B. DREGER]

Talk of IPv6 space hoarding and fragmentation. Ughh. Perhaps we can
avoid repeating IPv4 mistakes with IPv6.

Exponential problems need linear solutions.

The method for handing out blocks is flawed. There's no need for linear
stride-N allocations, assuming that a highly-sparse array is acceptable.

Allocate thus:

1. At start of 0b/1
2. At start of 1b/1
3. At start of 01b/2
4. At start of 11b/2
5. At start of 001b/3
6. At start of 101b/3
7. At start of 011b/3
8. At start of 111b/3
(and so forth)

Allocate on /1 boundaries as many times as possible... then /2...
followed by /3... next /4... et cetera. Let each allocation be long
enough to contain sufficient address space; the space to the right is
reserved for growth.

Different networks will grow at different speeds. That is handled by
allocating from "largest available /N" instead of "next /N in sequence",
and tends to keep new allocations away from rapidly-growing ones.

Fragmentation is drastically reduced. Allocating more space is a simple
matter of "grow right", reducing the "hoard as much as possible because
new space is a pain" mentality.

Wait... we've had this discussion before:

http://www.merit.edu/mail.archives/nanog/2006-03/msg00183.html


Eddy
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[David Conrad]

Hi,

Post by Edward B. DREGER
Talk of IPv6 space hoarding and fragmentation. Ughh. Perhaps we can
avoid repeating IPv4 mistakes with IPv6.

Would be nice, but alas, it seems we're doomed to repeat most past
mistakes.

Post by Edward B. DREGER
Let each allocation be long
enough to contain sufficient address space; the space to the right is
reserved for growth.

If I understand what you're suggesting, this is the rationale for the
RIR's receiving /12s from the IANA. The theory was that the RIRs
needed /12s in order for them to allocate address space via a
bisection methodology, which would allow for growth in any of the
allocations made.

However, last I checked (which was a while ago), only APNIC had
actually carried through on this -- all the other RIRs (if they were
allocating out of the /12 blocks at all), were still allocating
sequentially.

Things might have changed (haven't been following what the RIRs do so
closely anymore)...

Regards,
-drc

[Edward B. DREGER]

EBD> Date: Sat, 10 May 2008 04:02:49 +0000 (GMT)
EBD> From: Edward B. DREGER

EBD> Exponential problems need linear solutions.

Uhhhh.... that should read:

Exponential problems need logarithmic solutions.

(Activate... brain... before... engaging... fingers...)


Eddy
--
Everquick Internet - http://www.everquick.net/
A division of Brotsman & Dreger, Inc. - http://www.brotsman.com/
Bandwidth, consulting, e-commerce, hosting, and network building
Phone: [phone] Lawrence and [inter]national
Phone: [phone] Wichita
________________________________________________________________________
DO NOT send mail to the following addresses:
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Sending mail to spambait addresses is a great way to get blocked.
Ditto for broken OOO autoresponders and foolish AV software backscatter.