> Sent: Thursday, October 21, 2010 3:08 PM > To: George Bonser > Cc: Ben Butler; NANOG > Subject: Re: Only 5x IPv4 /8 remaining at IANA > > On Thu, Oct 21, 2010 at 12:53 PM, George Bonser <gbon...@seven.com> > wrote: > > 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. > > Why on earth would a registrar aggressively reclaim space from > entities if they're no longer issuing it back out?
To reduce the pool of available IPs, to reduce the reselling, transfer, hijacking of the space. As the amount of available v4 space declines, it becomes harder to obtain those resources for an operator either refusing to move or not wanting to move. It increases the incentive to move to v6 by making it increasingly difficult to operate in v4. I wouldn't recommend stopping the issuing of v4 space NOW, but maybe 5 years after runout. > Are we planning on recommending policies into the ARIN AC > that turn ARIN into an IPv4 space reclamation entity, to hoard > up v4 addresses? Ok, lets say runout occurs in 2011. Set a date, say 2016 after which ARIN will allocate IPv6 only. The idea isn't to hoard v4 addresses, the idea is to stop the allocation of new blocks. > As it now stands, the amount of v4 space being routed will trend > towards the asymptote of maximal organizational utilization, and will > *not* decline. Any organization that moves resources off v4 and > frees up address space will either hold that space as an ongoing > resource to be used for future expansions, or will sell it off on the > transfer market for short-term cash infusions; the new holders, > having paid good cash for it, will have a strong incentive to get it > routed and carrying traffic as quickly as possible, to pay back > their investment. For a while that is true. But what will the traffic look like 5 years from now? If most of the major user networks are migrated to v6 by that time and most of the major content providers are v6, and the amount of native v4 traffic declines, who is going to want v4 space for anything new? Servicing legacy stuff makes sense but in 2016 who is going to roll out new deployments in v4 space? And ARIN wouldn't be preventing them from doing that, they just wouldn't be able to get the addresses from ARIN. In other words, it would be a PITA to do that and much easier to roll out a new deployment with v6. By continuing to allocate v4 space, they would be enabling the running of v4 forever. > There is *nothing* in the system driving towards a natural attrition > of IPv4 usage, even after runout; we simply change the allocation > model from purely needs based, to needs+cash based. > > Unless ISPs state that they will charge additional money to > assign v4 addresses to customers, over what they charge > to v6 customers, there is no real pressure in the marketplace > for the amount of v4 routing to decline. So long as the end user > sees the same cost, and same service for using v4 as v6, there > is no pressure towards a v6-only world. Maybe. But look at it this way. Imagine 5 years from now a provider notices that only 1% of their traffic in a particular data center is v4. Rather than having to maintain dual-stack configurations on all the gear, they decide to allocate a pair of routers to v4 and go pure native v6 on all their customer facing stuff. Now maybe if the few people still using v4 want it, they can have it by tunneling 4 over 6 to that pair of routers. Now the vast majority of stuff in that provider's network is v6 only with only a couple of internal routers running v4 carrying the tunnels to their users who still use that space. Maybe 5 years after THAT in 2021 the amount of v4 traffic no longer justifies running v4 at all. Customers can still run v4 if they wish by tunneling to a v4 provider someplace else. Maybe even give the customers 5 MORE years to return their PA blocks, so now we are at 15 years from runout, the provider has reclaimed all their v4 space from their customers and returns it (maybe they have returned portions of that space before then) to ARIN and the provider no longer offers v4 services. So I wasn't talking about doing such a thing immediately, I had more of a phased approach in mind. 5 years from runout, ARIN stops issuing IPs. Within 10 years of runout, providers begin to shrink their v4 support, possibly tunneling the traffic to a single pair of routers in their network, 15 years after runout, most providers can't be bothered with v4 support but if you absolutely have to have it, someone can get it to you over a tunnel from someplace. 20 years from runout most providers have reclaimed all their PA space and have returned it to ARIN. > So...uh...who's going to be first to step up and tell their customers > "look, you get a v6 /56 for free with your account, but if you want > v4 addresses, it's going to cost an extra $50/month." ?? I wasn't talking about PA space allocated to a provider who in turn allocates that to customers. Providers could still issue/reclaim their own space as they wish. At some point, though, the tiny amount of traffic in that space begins to make it hard to justify having full v4 BGP tables at so many places. When the traffic dies to the point where all the provider's v4 traffic can be handled on a single pair of routers, it probably will be which will free up resources on the rest of the routers running native v6.
