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IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

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Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#41

Post by kbyers »

contextfree wrote: post #36
tptacek wrote: post #32

Earlier quoted context omitted.

It is, but not in the way you think. IPv4 addresses are also cognitively nasty (try to remember two of them, walk to the other end of your building, and recite them from memory). People don't often use them directly. The problem is that IPv4 addresses happen to fit in machine registers, and so virtually all of the world's networking software has been written to assume that they are just a gossamer-thin semantic layer…

Do you think it would have been better if they'd gone to a 64-bit format instead of 128-bit?

Yes, they definitely should have used 64-bits instead of 128-bits for the IPv6 address. At 64-bits, you have over 2 billion addresses per person on earth. At 128-bits, the number of addresses, you have is close to incomprehensible.

You don't need the host component of the IPv6 address to be 64-bits in length.

Also, they made the network component unnecessarily long in order to improve summarization. But until you solve the multi-homing problem summarization won't work.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#42

Post by randomtask »

m_eiman wrote: post #38
randomtask wrote: post #24

Earlier quoted context omitted.

This would be better done with a VPN than simply allowing external access to your printers.

That works until you're sitting behind another NAT that uses the same internal IP range as the one you connect to over VPN - which is very likely since everyone uses 192.168.0.0/24.

Assuming the VPN server doesn't just allocate from a pool of public IPs owned by the organisation you're connecting into (the scenario I had in mind here) then yes this is an issue.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#43

Post by tomjen3 »

tptacek wrote: post #29
wccrawford wrote: post #2

I don't think my router even supports IPv6. This is going to be -such- a fun transition. I really thought people would get serious about it 2 years ago.

Most of your software doesn't support IPv6, which I think is a bigger problem. Most everything that works with sockets assumes that a network address fits in a machine int type; IPv6 addresses aren't even scalar.

You computer have SSID registers, which are 128 bytes.

So it still fits.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#44

Post by kbyers »

nanijoe wrote: post #9

There are a lot of addresses that should be 'reclaimed' . These days, most enterprises really only need a few public addresses, and many of them are 'sitting on' large chunks of addresses they acquired in the 90s.

As opposed to "reclaiming" addresses i.e. returning addresses to the registries, we should come up with a scheme were institutions can sell their addresses (i.e. IPv4 addresses should become property). This would give institutions that possess very large blocks of addresses a large incentive to effectively utilize their address space.

We could go on for a long-time with IPv4 if the above were to occur.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#45

Post by jfr »

RodgerTheGreat wrote: post #28

I know this is going to sound silly, but it runs through my mind every time there's an IPv4/IPv6 discussion: Consider a pair of random IPs in standard written form: v4: 209.85.225.147 v6: 2001:db8:1f70::999:de8:7648:6e8 From a purely aesthetic standpoint, IPv6 addresses look nasty . They vary in length, they're hard to remember, they're a little bit harder to parse and print than v4s. Much like an email address, an I…

From a purely aesthetic standpoint, IPv6 addresses look nasty.

IP addresses are supposed to be used by machines, not humans (considering network administrators are not humans). Humans should deal with domain names.

They vary in length,

IPv4 addresses also do. strlen("10.1.2.4") == 8; strlen("192.168.123.234") == 15.

The physical addresses don't vary in either case. IPv4 is always 32 bit, IPv6 is always 128 bits.

they're hard to remember,

As an administrator, you can make the particular addresses that you need to remember simple. The last 80 bits of the address are entirely yours, and the first 48 bits are fixed for your entire organisation. With IPv4 you end up having multiple very different /24s dispersed through your organisation, and having to fit your important servers in whatever free address space you can find.

So, for example, you know that 2001:db8:1245::/48 is the prefix for your organisation. It is only one you have to remember. Then you can set your DNS to 2001:db8:1245::1, your web server to 2001:db8:1245::2, etc... Not hard to remember.

they're a little bit harder to parse and print than v4s

This is the sort of problem that you have to solve only once (and it was already solved), then use that function/library wherever you want. See inet_ntop(3) and getnameinfo(3) (as a bonus, these functions work identically to both IPv4 and IPv6, the application becomes agnostic to the address class being used).

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#46

Post by azim »

gamble wrote: post #35
tshtf wrote: post #34

Earlier quoted context omitted.

There certainly is. As of a couple of years ago IBM's 9.0.0.0/8 network was only used for their intranet and not routed outside. I believe several legacy /8's are in the same boat.

IIRC, HP is still sitting on three /8 networks - one from HP, Compaq, and DEC.

HP has two /8 blocks. Many people who at one point owned Class A blocks have given them back over the years. What's crazy, though is that the US Department of Defense still owns eleven /8 blocks.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#47

Post by Kadin »

DeusExMachina wrote: post #11
randomtask wrote: post #8

Earlier quoted context omitted.

> This is misleading: computers (and especially printers) attached to a local network do not deplete public IP addresses A device connected to a LAN in someone's house will often just have a private IP and go through a NAT for its internet access. However many big organisations will have been allocated a large address space at some point, often the size of a Class B. Their machines internally will often use a global…

Good point. I thought that there is not much use for a public IP for a printer, but I did not think about big address allocations. But is there any convenience in this? Can't they just switch a private LAN infrastructure connected through NAT?

If they have the allocation, why wouldn't they use it?

That's how IP was supposed to work. And once you've worked in a network where everyone has a real, non-RFC1918 address, you'll probably not want to go back. It just makes things really convenient; you never need to worry about address space collisions if you decide to connect two building networks together, for instance ... it's a whole lot more elegant than private addressing.

The places I've worked at that have legacy allocations have absolutely no interest in switching to RFC1918, and their allocation agreements are old enough that they don't contain any clawback provisions. It'll be "from my cold, dead hands" before they transition, and I can't blame them. It's how the Internet was supposed to work.

It's unfortunate that IPv6 got used as a way to shoehorn in a lot of stuff besides just increasing the address space. I've periodically seen much more conservative proposals that would have been less of a "forklift upgrade" and I think in retrospect it's unfortunate that these weren't considered.

But if IPv6 manages to kill or at least discourage the widespread use of RFC1918 addresses and bring back a more peer-to-peer architecture, it will be worth it in the long haul. The variety of applications and use cases we would be killing off without even knowing it by continuing down the path towards multiple layers of private addresses (because they just wouldn't be possible under that topology, and hence would never get developed) ought to sober anyone interested in development and new technology.

It may be possible for the Internet of today to work just fine with ISP-level NAT on top of home-network NAT, but if we resign ourselves to that we're shutting out a whole lot of interesting future possibilities that can only happen with an Internet that has end-to-end routability without second-class citizens. That would be truly sad.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#48

Post by tptacek »

joeyh wrote: post #39
tptacek wrote: post #32

Earlier quoted context omitted.

It is, but not in the way you think. IPv4 addresses are also cognitively nasty (try to remember two of them, walk to the other end of your building, and recite them from memory). People don't often use them directly. The problem is that IPv4 addresses happen to fit in machine registers, and so virtually all of the world's networking software has been written to assume that they are just a gossamer-thin semantic layer…

Out of curiosity, what software do you use that still lacks support for ipv6? Most everything I use has been ipv6-capabable for years. Earlier this week iftop got ipv6 support, and so the last non-ipv6-capable software I use is rtorrent. There are only about 100 packages out of all of Debian that have ipv6 problems: http://bugs.debian.org/tag:ipv6 My experience converting software to ipv6 has mostly been of convertin…

As you said, anything that uses gethostbyname(), or directly works with sin_addr.s_addr.

Here's the Microsoft guide:

http://msdn.microsoft.com/en-us/library/ms738649(VS.85).aspx

Note: I'm 100% sure Linux is much closer to IPv6 shangri-la than the rest of the world.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#49

Post by tptacek »

tomjen3 wrote: post #43
tptacek wrote: post #29

Earlier quoted context omitted.

Most of your software doesn't support IPv6, which I think is a bigger problem. Most everything that works with sockets assumes that a network address fits in a machine int type; IPv6 addresses aren't even scalar.

You computer have SSID registers, which are 128 bytes. So it still fits.

This is the moral equivalent of saying your computer has bignum libraries, so it still fits. Of course it does, if you use a bignum library.

Re: IPv4 Space Shrinks To 5% – Final Addresses To Be Issued In Early 2011

#50

Post by Kadin »

randomtask wrote: post #23
DeusExMachina wrote: post #11

Earlier quoted context omitted.

Good point. I thought that there is not much use for a public IP for a printer, but I did not think about big address allocations. But is there any convenience in this? Can't they just switch a private LAN infrastructure connected through NAT?

> Can't they just switch a private LAN infrastructure connected through NAT? They could and given that in most organisations devices are already generally subject to restrictive firewall rules it shouldn't impact them all that much. I think it would be better to focus efforts on making these organisations move to IPv6. This could possibly be achieved by ordering them to give back most of their IPv4 addresses. Since t…

> This could possibly be achieved by ordering them to give back most of their IPv4 addresses.

That would take years and cost millions of dollars, just for the lawyers.

New address allocations make it clear that you're really only being loaned the addresses -- but the old allocations didn't. Insofar as you can "own" a bunch of addresses, the companies and organizations with legacy allocations really do own them, and I suspect many of them (the ones that haven't voluntarily given them up already) probably aren't interested in giving them up and might decide to fight back.

Look over a list of Class As and tell me which you'd like to take on in court.

Obviously they could be bribed into giving those addresses up, if someone wanted to cover the cost of switching ... but if you're going to spend the money, there are probably better things you could do to spur IPv6 adoption than spend it on corporate networks with a well-defined upgrade policy. You'd probably do better to work with the big residential ISPs, or maybe with the wireless carriers, since that's where a lot of the new demand growth is.

The legacy allocation ship sailed a long time ago, and there are better things we can do now than try to chase it down and board it by force.

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