Only 5x IPv4 /8 remaining at IANA

George Bonser gbonser at seven.com
Thu Oct 21 19:53:51 UTC 2010



> From: Ben Butler 
> Sent: Thursday, October 21, 2010 10:18 AM
> To: 'Marshall Eubanks'
> Cc: NANOG
> Subject: RE: Only 5x IPv4 /8 remaining at IANA
> 
> Hi,
> 
> What is the consequence of not managing to transition the v4 network
> and having to maintain it indefinitely.  I think if the cost /
> limitations that this may place on things is great enough then the
> "how" will reveal itself with the interested parties.
> 
> Is there a downside to being stuck with both address spaces rather
than
> just 6, idk, you tell me, but there seems to be from what I can tell.
> 
> I am not suggesting any form of timeframe in the exact number of years
> / decades, just that a timeframe should exist where after a certain
> date - whatever that is - we can say ok, now we are turning off v4.

The first step will be a registrar saying "after this date, we will no
longer issue any IPv4 addresses for whatever reason" and at the same
time, getting very aggressive in reclaiming space from dead entities,
hijackers, etc.  As time goes by, the amount of v4 space being routed
declines through natural attrition.  It is a combination of liberal v6
assignment coupled with aggressive v4 reclamation.  

At some point the network operators themselves will announce their own
"drop dead" dates for supporting v4.  When the amount of v4 traffic
drops to some point where the infrastructure required to support it
becomes unreasonable, they will stop supporting it.  As v4 becomes
harder to route, it will become harder to find v4 providers ... sort of
like v6 is not available from *all* providers in a native sense today.
Sure, there will probably be people out there who will offer v4 over v6
tunnels long after most providers have stopped routing it sort of like 6
over 4 is offered today, but even those will become scarce at some
point.  

Once no more addresses are issued for any reason and once people stop
handling the traffic natively, it will die its own natural death and
kids entering the networking field will look at a v4 config and wonder
why it is even there.

> In the absence of any form of timeframe what is the operational
benefit
> of any existing v4 user migrating to v6 if the service provider is
> going to make magic happen that enables them to talk to v6 only host
> via some mysterious bridging box.  

Yeah, that does delay things but is required glue for the moment.

> I can see none, which tells me they
> are not going to bother spending there time and money renumbering and
> deploying v6 - ever! 

Yes they will, see above.

> There needs to be a technical, commercial or
> operational reason for them to want to go through the change.
> 
> Ben

Yeah, the "we decided to make a completely incompatible protocol with
really no other immediate technical benefit other than more address
space ... and each route takes up 4x more router resources" decision was
probably a bad call.

Heck, simply expanding the number of ports from 16 bit to 32 bit would
have greatly reduced ip address requirements from people having to add
IPs to NAT pools and other source NATs due to port exhaustion.






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