Knowledge base IPv4 management plans
Obviously, with the demise of the legacy IPv4 internet we have to consider our plans for how we will manage IPv4 address space over the coming years. These plans are not set in stone and will depend on take up of IPv6, the technology to support that (routers and so on) and growth in customer numbers, etc.
Basically, as an ISP, we will be able to get a final 1024 address block from RIPE at some time when we need it. We are at least months away from needing this. However, we will eventually get to a point where we have no more IPv4 addresses coming our way and have to consider steps to make best use of the addresses we have. We are very keen to avoid any sort of carrier level NAT on IPv4 for a wide variety of reasons.
Read about our plans for World IPv6 Launch 2012
Don't panic
The good news is that we have a plan, and that we have IPv4 addresses at present, so no need to panic right now. We have been running IPv6 for a long time and have services running on IPv6 as well as IPv4.
Recovery of our unused space
We have already been auditing internal usage of IP space and have some blocks we can now recover and re-use for customers. In some cases some final machines being relocated from one data centre to another, and similar work, mean we can free up some blocks.
Recovery of customer unused space
We suspect some customers with IPv4 allocations are not using them or not using the full allocations. We plan to audit usage and find such allocations, and talk to the customers. If they are happily using NAT or a proxy, and can reduce or release blocks, we will take them back.
PI space
Customers with /24 or bigger will be encouraged to apply for PI space which we will announce for them. Some of our larger wholesale customers are already registering as LIRs and swapping out IP space to free up larger allocations.
Recent changes in RIPE policy mean that even if you cannout justify a full /24 (256 addresses) you may be able to get PI space if you are multi-homing. We are working with at least one other ISP on providing multi-homed DSL connections which would allow you to have the same IP addresses from more than one ISP and qualify for a /24 of PI space. This is time limited as it will not be possible once RIPE are on their last /8 (expected mid 2012). Customers getting PI space free up the space they were using so we can assign it to other customers.
PI space does have an ongoing cost, but it is, in effect, your IP address space for as long as you want it, and we won't be imposing additional costs for customers using PI space. We can't just take it back because we need it, as it is not our IP space.
Encouraging IPv6
Customers using lots of IPv4 space will be encouraged to take up IPv6 and switch their global IP usage to IPv6 if possible. We aim to work with customers to help them make the transition as seamlessly as possible. Once their usage of the global IP space is all IPv6 they will be able to switch to proxies or NAT for IPv4 access to the legacy internet and free up addresses.
Charging for IPv4
In spite of our best efforts the day will come when we have to start charging for IPv4. This will be a motivator for companies to consider the options above and take on IPv6 as a solution to their networking requirements. This is something we will not do until necessary and will be notified well in advance. Hopefully this will not be needed as we should have convinced people to move to IPv6 properly and no longer need blocks of IPv4.
Reclaiming IPv4
It may be many years before we have to consider this, but ultimately we would rather that we are giving every customer a fixed WAN IPv4 address than maintaining IPv4 routed blocks to customers that refuse to switch to IPv6. Ultimately we can reclaim IPv4 space from such customers. This would be a very last resort and should never be needed as all of the previous steps should have amicably migrated businesses to IPv6 usage.
Non IPv4 connections
Eventually we may have customers that do not need any IPv4 addresses at all. We already have support for NAT64 to allow IPv6 only networks to access Legacy IPv4 machines on the internet, and we will prefer this as a solution than doing carrier IPv4 NAT. This is something people can try now, and by the time it is needed, some years in the future, the technology should be mature. However, we expect more and more of the services on the internet to be IPv6 by then and legacy IPv4 access to be an niche requirement.
