IP4 Space

Mark Newton newton at internode.com.au
Sat Mar 6 13:00:22 UTC 2010


On 06/03/2010, at 1:06 AM, David Conrad wrote:

> Mark,
> 
> On Mar 4, 2010, at 11:46 PM, Mark Newton wrote:
>> On 05/03/2010, at 2:50 PM, David Conrad wrote:
>>> When the IPv4 free pool is exhausted, I have a sneaking suspicion you'll quickly find that reclaiming pretty much any IPv4 space will quickly become worth the effort.
>> 
>> Only to the extent that the cost of IPv6 migration exceeds the cost
>> of recovering space.
> 
> You're remembering to include the cost of migrating both sides, for all combinations of sides interested in communicating, right?  In some cases, that cost for one of those sides will be quite high.

Yes, but I only need to pay the cost of my side.

>> There's sure to be an upper-bound on the cost of v4 space, limited by the
>> magnitude of effort required to do whatever you want to do without v4.
> 
> The interesting question is at what point _can_ you do what you want without IPv4.  It seems obvious that that point will be after the IPv4 free pool is exhausted, and as such, allocated-but-not-efficiently-used addresses will likely become worth the effort to reclaim.

That isn't a likely outcome, though.  We'll never need to do "without IPv4",
it'll always be available, just in a SP-NATted form which doesn't work very 
well.

Continuing to put up with that state of affairs comes with its own set of
costs and obstacles which need to be weighed up against the cost of 
migrating to dual-stack (unicast global IPv6 + SPNAT IPv4) to extract yourself
from the IPv4 tar-baby.  Not migrating will be increasingly expensive
over time, the costs of migrating will diminish, each individual operator
will reach their own point when staying where they are is more expensive
than getting with the program.

And most of the participants on this mailing list will probably reach
that point sooner than they think.

My mom will probably never see a need to move beyond IPv4.  But her next
door neighbor with the bittorrent client and WoW habit probably will, and
any content provider who's interested in having a relationship with their
eyeballs which isn't intermediated by bollocky SPNAT boxes probably will too.

Horses for courses.

What I do know is that this "migrating to IPv6 is expensive so nobody wants
to do it," is a canard that's been trotted out for most of the last decade
as a justification for doing nothing.

As an ISP that's running dual-stack right now, I can tell you from personal
experience that the cost impact is grossly overstated, and under the 
circumstances is probably better off ignored.

Just sayin'.

  - mark

--
Mark Newton                               Email:  newton at internode.com.au (W)
Network Engineer                          Email:  newton at atdot.dotat.org  (H)
Internode Pty Ltd                         Desk:   +61-8-82282999
"Network Man" - Anagram of "Mark Newton"  Mobile: +61-416-202-223









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