6 ms·

I feel like this blog does not accurately describe how large the ipv6 address space even after accounting for it being reduced by 2^64 for the host portion of t

I feel like this blog does not accurately describe how large the ipv6 address space even after accounting for it being reduced by 2^64 for the host portion of the address. If it did it would make the concerned comments about /28 ipv6 network sizes seem very misplaced. A single static ipv4 address is a /32 slice into the ipv4 space and is considered a reasonable to size give out to a single person or even a small business that asks for it. Of course larger companies and telecom operators need larger network allocations and they have gotten them for many years in the past. Now realize that if a /64 ipv6 network is the minimum size like a single ipv4 address then you see that the ipv6 address space has 2^32 /32 ipv6 networks. Now with ipv6 any technical person and acquire a entire ipv4 internet sized network in a continuous (globally routeable if you want) range. And if any sized business today can expect buy a single "class c" /24 range of ipv4 it makes sense that large global compaines get a ipv6 /20 network to run their entire network on it.For example cloudflare[1] uses 6 regional /32 networks and a /29 network for all their routing needs. Imaging trying to build cloudflare with less than 32 addresses in a single /24 ipv4 allocation. ipv6 is so large that you can just design your network without worrying about subnet size and route based on real policy or security boundaries alone. We will run out of MAC addresses before we run out of ipv6 [1] https://www.cloudflare.com/ips/ https://www.cloudflare.com/ips/

ahsteele 2y ago
It’s really hard to even comprehend how large IPv6 is. I have found that extreme examples tend to help people get there. Here are some I’ve used in the past. There are enough IPv6 Addresses for 4.77 x 10^28 for every living person. If each IPv6 address was a grain of sand… That’s 2.39 × 10^18 of addresses per person, or roughly enough sand sized addresses to equal about 1.8 times the volume of earths ocean per person. At sand scale all IPv6 addresses would take the volume of 12 sols. Conversely, all the IPv4 addresses in this sand scale would slightly over fill an oil drum. From “IPv6 Addresses: Big Numbers, Big Solutions”: https://www.osti.gov/servlets/purl/1365362 https://www.osti.gov/servlets/purl/1365362
- bruce511 2y ago
  Hah - all of those examples use a planet as comparison. The first 16 bits of the address should be reserved to be used by the Planetary Internet Addressing Council (PIAC) Allocating all addresses to Earth seems very shortsighted. (Some sarcasm should be assumed.) It doesn't really matter how you explain large-number math to people who are bad at large-number math (aka all of us) - there's always some bright-spark who misses the point.
  - Dylan16807 2y ago
    The moon can share with the earth, and anything further away needs special encapsulation to deal with hours or more of latency.
    - atq2119 2y ago
      It's only minutes for the inner planets. But of course that's already enough to require special treatment.
  - rvnx 2y ago
    Well we could argue that this support for trillions of IP addresses is nice, except that IPv6 does not technically work in interplanetary environments due to various hardcoded timeouts. The first martians are likely to run their own local network and then use a VPN over DTN for their everyday communications by email (and appear coming from a single IPv6 address). One good thing though: since most of the humanity’s knowledge is going to be packed in an LLM they won’t really actually need internet to learn about things. But lack of videos may be annoying.
    - remram 2y ago
      I see only one IPv6 timeout, for fragmented packet reassembly, in other words between reception of fragments. So it's a bound on jitter not latency, and I see no reason it couldn't be increased for interplanetary links.
- Dylan16807 2y ago
mike_d 2y ago
People get caught up in how many IPv6 addresses exist, as if we will always have enough to go around. Recently Capital One was assigned a /16, enough for every ATM in the US to be its own ISP and make its own customer allocations. We continue to repeat the same mistakes that made people believe we needed v6 in the first place. We will never run out of IPv6, but I believe in my lifetime you won't be able to get new v6 allocations anymore because they will have all been handed out to the large corporations with deep pockets. Oops, no addresses left - but you can rent one from a cloud provider for a few dollars a month.
- wpm 2y ago
  Then, we’ll make IPv8, with 2^1024 address, which will be incompatible with IPv6 and IPv4 and all software on release, and will take decades before any appreciable uptake. Addresses will use hexadecimal, as well as the entire 4-byte Unicode table of emoji and Egyptian hieroglyphics, with octet separated by $ and { symbols for heightened readability.
  - immibis 2y ago
    No, we won't do that.
  - zeristor 2y ago
    I believe IPv8 does something else: https://py-ipv8.readthedocs.io/en/latest/ https://py-ipv8.readthedocs.io/en/latest/
    - tribler 2y ago
      IPv8 dev here. Thnx for mentioning this. IETF draft standard of IPv8: https://datatracker.ietf.org/doc/html/draft-pouwelse-trustchain-01#section-4 https://datatracker.ietf.org/doc/html/draft-pouwelse-trustch... Bonus: "De-DSI" == LLM- based fuzzy search + IPv8
      - DonHopkins 2y ago
        The time the think of deploying IPv8 is BEFORE you've deployed something else. https://www.youtube.com/watch?v=qYo0lVVH2wU https://www.youtube.com/watch?v=qYo0lVVH2wU
cyberax 2y ago
Except that IPv6 is actually not that large. You effectively can't use networks that are smaller than /64, because stateless autoconfiguration can't use any other prefix size (there's an effort to fix it, but it'll take a decade at best)
- immibis 2y ago
  You can absolutely use them, you just need static or DHCP addressing just like the old days. But thanks SLAAC for forcing my ISP to give me /64 or bigger so I can always subnet into /96 for example.
  - pantalaimon 2y ago
    How many devices actually support DHCPv6? SLAAC is pretty much the standard way of assigning addresses these days.
    - jeroenhd 2y ago
      Just about anything with a screen these days. The biggest holdout is Android and a bunch of IoT stuff. SLAAC works on any device that supports DHCPv6, though, so you might as well use it if you don't have any requirements to favour DHCPv6
- ironhaven 2y ago
  That was my whole point. There are not 2^128 ipv6 addresses for Individual use but there are 2^64 /64 networks. If you rent a vps with a ipv6 “address” you will see that you are given a /64 network. There is no effort to “fix” the bottom 64 bits because it’s not needed. There are enough /56 networks to for the next 500 years and 99% of people can do everything they need with an isp provided /56. IPv4 has survived with 48 bit nat for this long so 64 bit is even more buffer space
  - jeroenhd 2y ago
    > If you rent a vps with a ipv6 “address” you will see that you are given a /64 network. Unfortunately, I've seen multiple VPS providers that will assign you a single address within a /120 or something ridiculous like that. I presume whoever runs the network side of things with those VPS providers has never used IPv6 themselves or they must be _extremely_ stingy.
tsimionescu 2y ago
The thing is, there are just as many /28 IPv6 ranges as /28 IPv4 ranges. And the experience with IPv4 is that it's those larger ranges that we've run out of the quickest. The whole power of IPv6 is that assigning a huge global business a /32 gives them enough addresses to run more devices that exist on the whole Internet today. But if we're distributing large swaths of IPv6, we'll run out just the same, unless we try to later claw them back like we did with some IPv4 /8 spaces. Now, of course, a /28 in IPv4 is a tiny range, while a /28 in IPv6 is huge. And there are, of course, a lot of /28s. The fear is only that we may start seeing larger and larger allocations for no good reason whatsoever. Apparently already some random private company (Capital One) has received a /16 IPv6 range - this is an absurd allocation that should simply not be allowed if we don't want to have to move to a new IP version in a few decades.
simne 2y ago
> does not accurately describe how large the ipv6 It is not the limitation, but router hardware is. Now problem mostly eased, thanks to Moore law, but 20 years ago router memory need to store prefixes-routes graph was very expensive and have some problems with grow. For example, I know people, bought very expensive server PC boards (but cheap compared to enterprise networking hardware), with DDR2 capability, because it was fastest at that time and promises large RAM space. Imagine their frustration, when they seen, this hardware cannot allocate prefixes list for their installation (just not enough RAM) and they have to buy new hardware with DDR3. This even caused "curse of /24", when some providers decided to just discard /24 prefixes and work only with /16 directly and for smaller allocations use some default route. And this is just because nature of Internet, which is by definition "network of networks", mean, in ideal case all networks should have peer connections at least to all first circle neighbor networks, but better if have peers to few first circles, plus connections to large local hubs. And now problem become harder, because of grow of p2p solutions, which by definition avoid hub model and use all peers directly. BTW, colleague from telecom share latest problem - few days ago appear huge traffic. In very short time found source - after appear new "Stalker" game, their developers made huge number of fixes, so fixes are larger than installation, and they somewhere bought so powerful distribution network, distribution of fixes flooded all connections for few days.
- remram 2y ago
  There are attempts to address that like LISP https://www.rfc-editor.org/rfc/rfc9300.html https://www.rfc-editor.org/rfc/rfc9300.html
deleted 2y ago
[deleted]
throw0101a 2y ago
> I feel like this blog does not accurately describe how large the ipv6 address space even after accounting for it being reduced by 2^64 for the host portion of the address. One way of thinking about it: * Stars in the Milky Way: 400 Billion * Galaxes in the universe: 2 Trillion So (4x10^11)x(2x10^12)=8x10^23 stars in the universe. * Size of IPv6 address space: 3.4x10^38 Find the ratio between addresses and stars: * 3.4x10^38 / 8x10^23 IPv6 offers about 430 trillion times more addresses than estimated stars in the universe. From Tom Coffee's presentation "An Enterprise IPv6 Address Planning Case-Study" * https://www.youtube.com/watch?v=7Tnh4upTOC4 https://www.youtube.com/watch?v=7Tnh4upTOC4 Perhaps in more human terms: on the surface of the Earth (including oceans), there are 8.4 IPv4 addresses per km^2. Not counting the oceans, that would be 28 IPv4 addresses per km^2 land. IPv6 gives 10^17 addresses per mm^2 (yes, square millimeter). In terms of volume, 10^8 IPv6 addresses per mm^3 throughout the Earth. Another way of looking at it: *math property: x^y = x^(a+b) = (x^a)x(x^b) * IPv4 addresses are 32 bits (2^32) * 2^32 ~ 4.3 billion * So the IPv4 Internet has ~4.3B devices on it * IPv6 subnets are 64 bits, /64 (2^64) So, an IPv6 2^64 subnet is the same as (2^32)x(2^32), which means (4.3B)x(IPv4 Internet). I.e., a single IPv6 subnet can hold the equivalent of four billion (IPv4) Internets.

ahsteele 2y ago

It’s really hard to even comprehend how large IPv6 is. I have found that extreme examples tend to help people get there. Here are some I’ve used in the past. There are enough IPv6 Addresses for 4.77 x 10^28 for every living person. If each IPv6 address was a grain of sand… That’s 2.39 × 10^18 of addresses per person, or roughly enough sand sized addresses to equal about 1.8 times the volume of earths ocean per person. At sand scale all IPv6 addresses would take the volume of 12 sols. Conversely, all the IPv4 addresses in this sand scale would slightly over fill an oil drum. From “IPv6 Addresses: Big Numbers, Big Solutions”: https://www.osti.gov/servlets/purl/1365362 https://www.osti.gov/servlets/purl/1365362

bruce511 2y ago
Hah - all of those examples use a planet as comparison. The first 16 bits of the address should be reserved to be used by the Planetary Internet Addressing Council (PIAC) Allocating all addresses to Earth seems very shortsighted. (Some sarcasm should be assumed.) It doesn't really matter how you explain large-number math to people who are bad at large-number math (aka all of us) - there's always some bright-spark who misses the point.
- Dylan16807 2y ago
  The moon can share with the earth, and anything further away needs special encapsulation to deal with hours or more of latency.
  - atq2119 2y ago
    It's only minutes for the inner planets. But of course that's already enough to require special treatment.
- rvnx 2y ago
  Well we could argue that this support for trillions of IP addresses is nice, except that IPv6 does not technically work in interplanetary environments due to various hardcoded timeouts. The first martians are likely to run their own local network and then use a VPN over DTN for their everyday communications by email (and appear coming from a single IPv6 address). One good thing though: since most of the humanity’s knowledge is going to be packed in an LLM they won’t really actually need internet to learn about things. But lack of videos may be annoying.
  - remram 2y ago
    I see only one IPv6 timeout, for fragmented packet reassembly, in other words between reception of fragments. So it's a bound on jitter not latency, and I see no reason it couldn't be increased for interplanetary links.
Dylan16807 2y ago

mike_d 2y ago

People get caught up in how many IPv6 addresses exist, as if we will always have enough to go around. Recently Capital One was assigned a /16, enough for every ATM in the US to be its own ISP and make its own customer allocations. We continue to repeat the same mistakes that made people believe we needed v6 in the first place. We will never run out of IPv6, but I believe in my lifetime you won't be able to get new v6 allocations anymore because they will have all been handed out to the large corporations with deep pockets. Oops, no addresses left - but you can rent one from a cloud provider for a few dollars a month.

wpm 2y ago
Then, we’ll make IPv8, with 2^1024 address, which will be incompatible with IPv6 and IPv4 and all software on release, and will take decades before any appreciable uptake. Addresses will use hexadecimal, as well as the entire 4-byte Unicode table of emoji and Egyptian hieroglyphics, with octet separated by $ and { symbols for heightened readability.
- immibis 2y ago
  No, we won't do that.
- zeristor 2y ago
  I believe IPv8 does something else: https://py-ipv8.readthedocs.io/en/latest/ https://py-ipv8.readthedocs.io/en/latest/
  - tribler 2y ago
    IPv8 dev here. Thnx for mentioning this. IETF draft standard of IPv8: https://datatracker.ietf.org/doc/html/draft-pouwelse-trustchain-01#section-4 https://datatracker.ietf.org/doc/html/draft-pouwelse-trustch... Bonus: "De-DSI" == LLM- based fuzzy search + IPv8
    - DonHopkins 2y ago
      The time the think of deploying IPv8 is BEFORE you've deployed something else. https://www.youtube.com/watch?v=qYo0lVVH2wU https://www.youtube.com/watch?v=qYo0lVVH2wU

cyberax 2y ago

Except that IPv6 is actually not that large. You effectively can't use networks that are smaller than /64, because stateless autoconfiguration can't use any other prefix size (there's an effort to fix it, but it'll take a decade at best)

immibis 2y ago
You can absolutely use them, you just need static or DHCP addressing just like the old days. But thanks SLAAC for forcing my ISP to give me /64 or bigger so I can always subnet into /96 for example.
- pantalaimon 2y ago
  How many devices actually support DHCPv6? SLAAC is pretty much the standard way of assigning addresses these days.
  - jeroenhd 2y ago
    Just about anything with a screen these days. The biggest holdout is Android and a bunch of IoT stuff. SLAAC works on any device that supports DHCPv6, though, so you might as well use it if you don't have any requirements to favour DHCPv6
ironhaven 2y ago
That was my whole point. There are not 2^128 ipv6 addresses for Individual use but there are 2^64 /64 networks. If you rent a vps with a ipv6 “address” you will see that you are given a /64 network. There is no effort to “fix” the bottom 64 bits because it’s not needed. There are enough /56 networks to for the next 500 years and 99% of people can do everything they need with an isp provided /56. IPv4 has survived with 48 bit nat for this long so 64 bit is even more buffer space
- jeroenhd 2y ago
  > If you rent a vps with a ipv6 “address” you will see that you are given a /64 network. Unfortunately, I've seen multiple VPS providers that will assign you a single address within a /120 or something ridiculous like that. I presume whoever runs the network side of things with those VPS providers has never used IPv6 themselves or they must be _extremely_ stingy.

tsimionescu 2y ago

The thing is, there are just as many /28 IPv6 ranges as /28 IPv4 ranges. And the experience with IPv4 is that it's those larger ranges that we've run out of the quickest. The whole power of IPv6 is that assigning a huge global business a /32 gives them enough addresses to run more devices that exist on the whole Internet today. But if we're distributing large swaths of IPv6, we'll run out just the same, unless we try to later claw them back like we did with some IPv4 /8 spaces. Now, of course, a /28 in IPv4 is a tiny range, while a /28 in IPv6 is huge. And there are, of course, a lot of /28s. The fear is only that we may start seeing larger and larger allocations for no good reason whatsoever. Apparently already some random private company (Capital One) has received a /16 IPv6 range - this is an absurd allocation that should simply not be allowed if we don't want to have to move to a new IP version in a few decades.

simne 2y ago

> does not accurately describe how large the ipv6 It is not the limitation, but router hardware is. Now problem mostly eased, thanks to Moore law, but 20 years ago router memory need to store prefixes-routes graph was very expensive and have some problems with grow. For example, I know people, bought very expensive server PC boards (but cheap compared to enterprise networking hardware), with DDR2 capability, because it was fastest at that time and promises large RAM space. Imagine their frustration, when they seen, this hardware cannot allocate prefixes list for their installation (just not enough RAM) and they have to buy new hardware with DDR3. This even caused "curse of /24", when some providers decided to just discard /24 prefixes and work only with /16 directly and for smaller allocations use some default route. And this is just because nature of Internet, which is by definition "network of networks", mean, in ideal case all networks should have peer connections at least to all first circle neighbor networks, but better if have peers to few first circles, plus connections to large local hubs. And now problem become harder, because of grow of p2p solutions, which by definition avoid hub model and use all peers directly. BTW, colleague from telecom share latest problem - few days ago appear huge traffic. In very short time found source - after appear new "Stalker" game, their developers made huge number of fixes, so fixes are larger than installation, and they somewhere bought so powerful distribution network, distribution of fixes flooded all connections for few days.

remram 2y ago
There are attempts to address that like LISP https://www.rfc-editor.org/rfc/rfc9300.html https://www.rfc-editor.org/rfc/rfc9300.html

deleted 2y ago

[deleted]

throw0101a 2y ago

> I feel like this blog does not accurately describe how large the ipv6 address space even after accounting for it being reduced by 2^64 for the host portion of the address. One way of thinking about it: * Stars in the Milky Way: 400 Billion * Galaxes in the universe: 2 Trillion So (4x10^11)x(2x10^12)=8x10^23 stars in the universe. * Size of IPv6 address space: 3.4x10^38 Find the ratio between addresses and stars: * 3.4x10^38 / 8x10^23 IPv6 offers about 430 trillion times more addresses than estimated stars in the universe. From Tom Coffee's presentation "An Enterprise IPv6 Address Planning Case-Study" * https://www.youtube.com/watch?v=7Tnh4upTOC4 https://www.youtube.com/watch?v=7Tnh4upTOC4 Perhaps in more human terms: on the surface of the Earth (including oceans), there are 8.4 IPv4 addresses per km^2. Not counting the oceans, that would be 28 IPv4 addresses per km^2 land. IPv6 gives 10^17 addresses per mm^2 (yes, square millimeter). In terms of volume, 10^8 IPv6 addresses per mm^3 throughout the Earth. Another way of looking at it: *math property: x^y = x^(a+b) = (x^a)x(x^b) * IPv4 addresses are 32 bits (2^32) * 2^32 ~ 4.3 billion * So the IPv4 Internet has ~4.3B devices on it * IPv6 subnets are 64 bits, /64 (2^64) So, an IPv6 2^64 subnet is the same as (2^32)x(2^32), which means (4.3B)x(IPv4 Internet). I.e., a single IPv6 subnet can hold the equivalent of four billion (IPv4) Internets.