4 ms·

Yes, I was wondering if I was missing something reading the hypothetical: This is still splits the Internet into two incompatible (but often bridged etc.) subne

by lxgr 8mo ago

Yes, I was wondering if I was missing something reading the hypothetical: This is still splits the Internet into two incompatible (but often bridged etc.) subnetworks, one on the v4, one on the v4x side, right? It just so happens that, unlike for v6, v4 and v4x have some "implicit bridges" built-in (i.e. between everything in v4 and everything in v4x that happens to have the last 96 bits unset). Not sure if that actually makes anything better or just kicks the can down the road in an even more messy way.

xorcist 8mo ago
> everything in v4x that happens to have the last 96 bits unset That's pretty much identical to 6in4 and similar proposals. The Internet really needs a variant of the "So, you have an anti spam proposal" meme that used to be popular. Yes, it kill fresh ideas in the bud sometimes, but it also helps establish a cultural baseline for what is constructive discussion. Nobody needs to hear about the same old ideas that were subsumed by IPv6 because they required a flag day, delayed address exhaustion only about six months, or exploded routing tables to impossible sizes. If you have new ideas, let's hear them, but the discussion around v6 has been on constant repeat since before it was finalized and that's not useful to anyone.
- lxgr 8mo ago
  I feel like the greatest vindication of v6 is that I’m reading the same old arguments served over a quietly working v6 connection more often than not. While people were busy betting on the non-adoption of v6, it just happened. —Sent from my IPv6 phone
  - setr 8mo ago
    I don’t know if it anyone was really making bets around it… it’s just kind of individually meaningless to implement support for until it’s already popular, because you still have to support IPv4 in full until the day you can remove it entirely
- throw0101d 8mo ago
  > The Internet really needs a variant of the "So, you have an anti spam proposal" meme that used to be popular. For those unfamiliar: * https://craphound.com/spamsolutions.txt https://craphound.com/spamsolutions.txt
  - dullcrisp 8mo ago
    Public reluctance to accept weird new forms of money has turned out to be a myth.
    - marcus_holmes 8mo ago
      I don't think that's true. There are a ton of weird coins around, sure, but no-one is using them as money. I still have to stump up actual dollars backed by a government if I want to buy a coffee.
- billpg 8mo ago
  This wasn't a proposal, but an alternate history. The world where the people who wished for IPv4 but with extra address space get their way. By the end I come down on being happy with we're in the IPv6 world, but wishing interoperability could be slicker.
wmf 8mo ago
IPv6 had an implicit bridge called 6to4 but it was phased out because it wasn't that reliable.
- perennialmind 8mo ago
  There was no upside for an ISP to operate a 6to4 relay, so the anycast address was worse than a blackhole route. It would occasionally permit a connection, but mostly just caused timeouts. Without that poison pill, it could have been a nice way to allow for connecting private subnets that otherwise use conflicting RFC1918 subnets. That's what I used it for.
  - Dagger2 8mo ago
    Two 6to4 networks will communicate directly between each other without using a relay, so it will still work for that. Although you ought to be able to use native v6 these days. If you can't deploy v6 (whether native or 6to4) on the remote side for whatever reason, NAT64 is useful for dealing with conflicting RFC1918. You map each instance of RFC1918 you need to access into different v6 /96s, and then they don't conflict from your perspective. (But like NAT44, it only works for outbound connections; inbound ones need a port forward.)
joseda-hg 8mo ago
I might be interpreting wrong, but doesn't IPv6 also have a "implicit bridge" for IPv4?
- billpg 8mo ago
  If it does that's great, but why couldn't I connect to IPv6-only services back when my ISP was IPv4 only?
  - joseda-hg 8mo ago
    It's one way, v6 is aware of v4, but not the other way around
- pocksuppet 8mo ago
  It's not automatic, there were many proposed and utilized mechanisms for autodetecting translation servers and so on. By now though, if you want IPv6, you order real IPv6, and don't need some translation.
deleted 8mo ago
[deleted]
throw0101d 8mo ago
> It just so happens that, unlike for v6, v4 and v4x have some "implicit bridges" built-in (i.e. between everything in v4 and everything in v4x that happens to have the last 96 bits unset). See perhaps: > For any 32-bit global IPv4 address that is assigned to a host, a 48-bit 6to4 IPv6 prefix can be constructed for use by that host (and if applicable the network behind it) by appending the IPv4 address to 2002::/16. > For example, the global IPv4 address 192.0.2.4 has the corresponding 6to4 prefix 2002:c000:0204::/48. This gives a prefix length of 48 bits, which leaves room for a 16-bit subnet field and 64 bit host addresses within the subnets. * https://en.wikipedia.org/wiki/6to4 https://en.wikipedia.org/wiki/6to4 Have an IPv4 address? Congratulations! You get entire IPv6 /48 for free.
- perennialmind 8mo ago
  As I recall, 6to4 worked beautifully between 6to4 nodes in the absence of middlebox interference. The fatal flaw was the anycast address for accessing the "real" IPv6 network. The rosy outcome imagined in the article doesn't require a hypothetical IPv4 extension: just the novel idea of leaving the IPv4 core alone and extending the edge - which would have brought the financial incentives into alignment.

by lxgr 8mo ago

xorcist 8mo ago

> everything in v4x that happens to have the last 96 bits unset That's pretty much identical to 6in4 and similar proposals. The Internet really needs a variant of the "So, you have an anti spam proposal" meme that used to be popular. Yes, it kill fresh ideas in the bud sometimes, but it also helps establish a cultural baseline for what is constructive discussion. Nobody needs to hear about the same old ideas that were subsumed by IPv6 because they required a flag day, delayed address exhaustion only about six months, or exploded routing tables to impossible sizes. If you have new ideas, let's hear them, but the discussion around v6 has been on constant repeat since before it was finalized and that's not useful to anyone.

lxgr 8mo ago
I feel like the greatest vindication of v6 is that I’m reading the same old arguments served over a quietly working v6 connection more often than not. While people were busy betting on the non-adoption of v6, it just happened. —Sent from my IPv6 phone
- setr 8mo ago
  I don’t know if it anyone was really making bets around it… it’s just kind of individually meaningless to implement support for until it’s already popular, because you still have to support IPv4 in full until the day you can remove it entirely
throw0101d 8mo ago
> The Internet really needs a variant of the "So, you have an anti spam proposal" meme that used to be popular. For those unfamiliar: * https://craphound.com/spamsolutions.txt https://craphound.com/spamsolutions.txt
- dullcrisp 8mo ago
  Public reluctance to accept weird new forms of money has turned out to be a myth.
  - marcus_holmes 8mo ago
    I don't think that's true. There are a ton of weird coins around, sure, but no-one is using them as money. I still have to stump up actual dollars backed by a government if I want to buy a coffee.
billpg 8mo ago
This wasn't a proposal, but an alternate history. The world where the people who wished for IPv4 but with extra address space get their way. By the end I come down on being happy with we're in the IPv6 world, but wishing interoperability could be slicker.

wmf 8mo ago

IPv6 had an implicit bridge called 6to4 but it was phased out because it wasn't that reliable.

perennialmind 8mo ago
There was no upside for an ISP to operate a 6to4 relay, so the anycast address was worse than a blackhole route. It would occasionally permit a connection, but mostly just caused timeouts. Without that poison pill, it could have been a nice way to allow for connecting private subnets that otherwise use conflicting RFC1918 subnets. That's what I used it for.
- Dagger2 8mo ago
  Two 6to4 networks will communicate directly between each other without using a relay, so it will still work for that. Although you ought to be able to use native v6 these days. If you can't deploy v6 (whether native or 6to4) on the remote side for whatever reason, NAT64 is useful for dealing with conflicting RFC1918. You map each instance of RFC1918 you need to access into different v6 /96s, and then they don't conflict from your perspective. (But like NAT44, it only works for outbound connections; inbound ones need a port forward.)

joseda-hg 8mo ago

I might be interpreting wrong, but doesn't IPv6 also have a "implicit bridge" for IPv4?

billpg 8mo ago
If it does that's great, but why couldn't I connect to IPv6-only services back when my ISP was IPv4 only?
- joseda-hg 8mo ago
  It's one way, v6 is aware of v4, but not the other way around
pocksuppet 8mo ago
It's not automatic, there were many proposed and utilized mechanisms for autodetecting translation servers and so on. By now though, if you want IPv6, you order real IPv6, and don't need some translation.

deleted 8mo ago

[deleted]

throw0101d 8mo ago

> It just so happens that, unlike for v6, v4 and v4x have some "implicit bridges" built-in (i.e. between everything in v4 and everything in v4x that happens to have the last 96 bits unset). See perhaps: > For any 32-bit global IPv4 address that is assigned to a host, a 48-bit 6to4 IPv6 prefix can be constructed for use by that host (and if applicable the network behind it) by appending the IPv4 address to 2002::/16. > For example, the global IPv4 address 192.0.2.4 has the corresponding 6to4 prefix 2002:c000:0204::/48. This gives a prefix length of 48 bits, which leaves room for a 16-bit subnet field and 64 bit host addresses within the subnets. * https://en.wikipedia.org/wiki/6to4 https://en.wikipedia.org/wiki/6to4 Have an IPv4 address? Congratulations! You get entire IPv6 /48 for free.

perennialmind 8mo ago
As I recall, 6to4 worked beautifully between 6to4 nodes in the absence of middlebox interference. The fatal flaw was the anycast address for accessing the "real" IPv6 network. The rosy outcome imagined in the article doesn't require a hypothetical IPv4 extension: just the novel idea of leaving the IPv4 core alone and extending the edge - which would have brought the financial incentives into alignment.