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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

#32

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…

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 on top of a scalar integer. IPv6 addresses emphatically do not work as scalar integers.

It's not just that this means you can't do math on an IPv6 address (though without a bignum library you can't). It's also the case that, as far as a lot of C programmers are concerned, you can't even directly assign them; they're "memcpy big".

When Daniel J. Bernstein talks about the "IPv6 mess", this is one of the things he's talking about; it's not just that the whole world needs to be renumbered (note: hasn't ever been done before), but also that all our software needs to be upgraded.

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

#33
post #10

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.

Devices that don't support IPv6, or don't have IPv6 enabled, will just share an IPV4 address in a NAT pool at the ISP level. It's not pretty but it works.

That still means that everything anyone wants to get to needs to be dual-stacked for the forseeable future.

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

#34
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.

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.

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

#35
post #34
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.

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.

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

#36
post #32

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…

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?

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

#37
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?

I think 32 bits are fine, because I think IP addresses should be to 2020 what ethernet addresses were to 1994. We shouldn't forklift out IPv4; we should build a new city on the ruins.

More direct answer: yeah, I think 64 bits is a more reasonable addressing size, particularly if you accept the notion of second-class entities (that is to say, that the 15th heat sensor inside your toaster just might be OK with an RFC19180 private /8 address relayed through the toaster master control system's publicly routable address).

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

#38

Earlier quoted context omitted.

Printing from off-site is easier with a public IP, I don't know how often that is necessary.

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.

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

#39
post #32

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…

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 converting from gethostbyname(3) to getaddrinfo(3), and those are really the common cases for anything that simply needs to do dns lookups. Neither exposes an IP address outside a semi-opaque structure.

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

#40

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…

I remember hearing some apocryphal story about a tech being frustrated that the numpad on your keyboard doesn't have a-f or ':' keys. Another way in which it doesn't fit with the way we do things in v4.

More to your point, I think this illustrates two things -- the need to use DNS more instead of static numbering in v6, and to number your infrastructure in the lowest /48 or /64 subnet of your allocation so that you can enjoy the benefit of omission of leading zeros for things you might actually need to type in by hand (e.g. 2001:db8:1f70::1)

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