Only 5? You're not thinking big enough!

As many IPs as you want per computer. Go nuts!

Back before the exhaustion policies kicked in, ARIN were burning through a /8 every couple of months.

This is why taking back the legacy address allocations will not really be worth the time or effort. There is more demand than availability. If there was free reign allocation over it all, it would be gone before the year is out.

Move to IPv6 already.

Oh, and 11/8 recently became routable.

What now? PI space is normal routable space that you take between providers. Nothing to do with relays...

https://en.wikipedia.org/wiki/...

This really depends on your region. My knowledge if from RIPE. The default allocation there is now a /29. But that is default. If you can justify more, you can have more.

Partially from a previous comment I've made:

Imagine that everyone on the planet is connected, and they each have 32 different ISPs (phones, home, work...) This is a gross overestimation.

7 billion people * 32 = 224 000 000 000 /48's required.

This easily fits within a single /10. That is 1/1024 of the total address space.

IPv4 currently has been around since around 1980 (Can't be bothered to get real dates). This means that it has so far had a life of around 40 years.

IPv6 is not going to last forever. It is very likely we will hit some limitation of the protocol, but its not likely to be with the address space. Lets use the IPv4 life length as a ball park figure for how long its going to last us.

Lets imagine in that time the population doubles, and the number of ISPs that everyone has doubles in that time.

We now have 14 billion people and 64 ISPs

14 billion people * 64 = 896 000 000 000 /48s required.

This comfortably fits within a /8 or 1/256 of the available address space.

Now we can do sparse addressing and leave big holes in the allocations "just in case" but we are still going to have a hell of a lot of address space left at this point.

Since we don't expect this protocol to last forever, why potentially stifle innovation by limiting addresses, when even using really outlandish figures for what may happen still leaves us with huge swaths of address space unused?

The current best practice allocation policies only affect the first /3, or 1/8 of the total available space. If we manage to burn through that quicker than expected, policies can be adjusted for the next /3.

I will begrudgingly accept for an ISP to hand me a /60 or a /56, but personally, I will be giving all my customers a /48. The space is so massive it seems rude not to.

If you run a business and need your address space to never change, like when changing ISP, then PI (provider independent) address space is the way to go. The address space will always be yours, and you can take it with you.

For residential users who like to know where their devices are... that one is a bit tougher. Really DNS is your friend. How often do you change ISPs anyway?

And from the RIPE address plan manual

"So a /48 should be used when there is any doubt whether a /56 is sufficient in the long run. ISPs
get much leeway in determining the prefix size they give to their customers up to /48–even in
the case of home users"

I would say there is always a doubt that a /56 may be insufficient. A /56 only allows for 256 networks.

Microsoft http://www.networkworld.com/ar...

Why wouldn't they?

The IPv6 address space is so huge that you can give every person on the planet multiple /48's, and barely make a dent in the free pool.

Unnecessarily withholding address space may stifle innovation. A /48 is a lot of address space, but we will be kicking ourselves if we allocate less, and an application comes along that requires a load of networks.

You can go to he.net, sign up for a free tunnel, and click 'Give me a /48'. No questions asked.

FYI, I have native IPv6 connectivity at home with a /48 assigned.

I also work for a (different) ISP, and our policy is every connection gets a /48.

It simplifies addressing policies at the very least.

Unfortunately there is no such policy (and if there were, it would be unenforceable)

The RECOMMENDATION is to give a /48 per customer. This includes to things like mobile phones, broadband etc. This is fairly sensible.

Unfortunately there are still people stuck in the 'we must conserve address space' mindset from IPv4.

What is the point? Under the 'normal' allocation policy a /8 was being burned through every few months per region. The demand is still there (RIPE, LACNIC, and APNIC haven't had any addresses for ages). You can 'take back' the 20 or so /8s, and that will buy us a year at most.

The specification defines a network as using a /64. Period. None of this altering the network size to conserve addresses we needed in IPv4.

The smallest allocation any site should ever be given is defined as a /48. This give every site 65566 networks of size /64.

What a lot of people seem to have problems understanding is the vast size of IPv6.

Imagine that everyone on the planet is connected, and they each have 32 different ISPs (phones, home, work...) This is a gross overestimation.

7 x billion people * 32 = 224 000 000 000 /48's required.

This easily fits within a single /10. That is 1/1024 of the total address space.

The current addressing policies were required due to the finite nature of IPv4. IPv6 is still finite, but the scale is vastly different.

The current allocation policies only affect the first /3, or 1/8 of the total available space. If we manage to burn through that quicker than expected, policies can be adjusted for the next /3.

AfraNIC do not have a shitload of addresses. They have around 2.5 /8's.

Back before the exhaustion policies kicked in, ARIN were burning through a /8 every couple of months.

This is why taking back the legacy address allocations will not really be worth the time or effort. There is more demand than availability. If there was free reign allocation over it all, it would be gone before the year is out.

Move to IPv6 already.

No they don't. Classfull addressing was deprecated over 20 years ago. They may have a /16. (Obligatory wikipedia link https://en.wikipedia.org/wiki/...)

Excellent! This is the way it should be done (firewall part aside). A globally routable IP address per machine is the dream!

Reclaiming address space just isn't worth the time. At its peak, ARIN (the RIR for North America) was going through a /8 in a few months. These days there is a lot of buzz about 'The Internet of Things'. Whether you buy into all that or not, its just not possible to address every machine they are talking about out of the IPv4 address space.

They have contemplated doing things like making 240/4 routable, but it wouldn't last a year if allocations were allowed to run at the rate they would with no limitations. Reclaiming address space (even if they could) from organisations that 'don't need it' would give the Internet a year of growth at best.

There probably is a lot of waste in IPv4 address space, but we shouldn't be citing that as a reason not to change. At some point - even if we put in the effort to reclaim all the 'waste' - we are going to run out. Why spend all that energy reclaiming instead of just deploying v6?

I would not agree with you here. The motivation is a larger address pool.

This is a lot of rage. I'm clearly pro-IPv6. I'm aware of the limitations in address space in IPv4. I'm aware that IPv6 adds 96 more bits, and makes the space ridiculously large. My point was merely an observation on why the uptake has been slow. The ISP I work for is in the habit of making any new purchase or deploying anything new IPv6 capable. I think a lot of operators with clue are doing the same.

I don't think that you can disagree my point though? If IPv4 and IPv6 were able to interop, then uptake would have been much quicker.

Oh, and a lot of decisions made when IPv6 was being developed was around complexity. Routers were really starting to struggle around then. This was basically the reason that MPLS was created for. Hardware got quicker first though. Had IPv6 been developed 10 years later then a very different beast would have emerged. Hindsight is a wonderful thing though.

Exactly this.

The problem occurs when you have an IPv4 VPN tunnel, and IPv6 native connectivity. The IPv6 connectivity will be preferred over the IPv4 tunnel, and you will connect natively.

The fix? There are two

1) Add IPv6 support to the VPN, and default route traffic over that.
2) Drop the IPv6 connection while connected to the VPN.

The first solution is obviously best.