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Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

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Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#41

Post by dboreham »

dangerlibrary wrote: post #8

It never made sense to me why the authors of the IPv6 standard chose to use an entirely different address format, instead of extending address space in a backwards-compatible way. Why not just append/prepend the 12 additional bytes onto existing IPv4 addresses, and write the standard such that all valid IPv4 addresses are also valid IPv6 addresses? I'm not an RFC author, but something like "All existing IPv4 addresse…

Also, a meta-reply would be: whatever clever solution you think you've invented was surely considered. It's 30 years ago so memory fades but all this was discussed at great lengths on mailing lists and in meetings by people who knew what they were doing. The only things I don't think were envisioned at the time were: NAT prolonging the V4 space exhaustion significantly, and the level of inertia for vendors implementing support for V6. I was still working on that in 2005 -- more than 10 years later.

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#42

Post by kstrauser »

tgma wrote: post #22

djb on IPv6 incompatibility being a bad design choice: https://cr.yp.to/djbdns/ipv6mess.html

His points were wrong 22 years ago, and they continue to be wrong today. It's a poor document to cite as a rationale for avoiding IPv6.

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#43

Post by dvh »

dangerlibrary wrote: post #8

It never made sense to me why the authors of the IPv6 standard chose to use an entirely different address format, instead of extending address space in a backwards-compatible way. Why not just append/prepend the 12 additional bytes onto existing IPv4 addresses, and write the standard such that all valid IPv4 addresses are also valid IPv6 addresses? I'm not an RFC author, but something like "All existing IPv4 addresse…

https://en.wikipedia.org/wiki/Second-system_effect

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#44

Post by unilynx »

solatic wrote: post #30

Incredibly unsafe. If Class E is reserved "for future use", maybe that could include public use. The first rule of hardening production reliability is, make sure it doesn't just work, but that it will continue to work. Tomorrow, some customer of yours gets assigned addresses from Class E. Have fun untangling that. Why not stop this bullshit and just transition to IPv6??

class E can't ever be used on the public internet anyway. too many existing firewalls are already configured to drop anything with a source address in range 224.0.0.0-255.255.255.255 (class D and E)

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#45

Post by yjftsjthsd-h »

api wrote: post #37
yjftsjthsd-h wrote: post #34

Earlier quoted context omitted.

> and DHCPv6 So long as you don't have to care about Android, maybe.

Android still doesn't have this?

AFAIK https://issuetracker.google.com/issues/36949085 is still current.

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#46

Post by wmf »

api wrote: post #37
yjftsjthsd-h wrote: post #34

Earlier quoted context omitted.

> and DHCPv6 So long as you don't have to care about Android, maybe.

Android still doesn't have this?

Android is kind of boycotting DHCPv6 which annoys network admins.

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#47

Post by Ekaros »

BenjiWiebe wrote: post #17
DanAtC wrote: post #14

Earlier quoted context omitted.

There's no such thing as "backwards compatible." The IPv4 packet format is set in stone with 32 bit addresses. The "just add more bytes" meme doesn't make any sense.

But it gets brought up all the time ...

Makes me really doubt about general education in CS and programming.

Is there really this many people who never looked what is in IP packet. And well TCP and UDP too, but less so. Or considered how a packet might traverse across networks.

You have a small box, and that is it. You cannot make box bigger and make someone that only understand small box to understand the new big box.

Then on other end there are those that are too stuck of manually managing the small boxes... And the stuff that made them somewhat usable.

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#48

Post by wmf »

dvh wrote: post #43
dangerlibrary wrote: post #8

It never made sense to me why the authors of the IPv6 standard chose to use an entirely different address format, instead of extending address space in a backwards-compatible way. Why not just append/prepend the 12 additional bytes onto existing IPv4 addresses, and write the standard such that all valid IPv4 addresses are also valid IPv6 addresses? I'm not an RFC author, but something like "All existing IPv4 addresse…

https://en.wikipedia.org/wiki/Second-system_effect

IPv6 definitely suffers from some amount of second-system effect but (I cannot stress this enough) that's not the cause of its failure. A minimal IPv4+ upgrade would still have failed for the same reasons.

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#49

Post by Ekaros »

BadBadJellyBean wrote: post #11
dangerlibrary wrote: post #8

It never made sense to me why the authors of the IPv6 standard chose to use an entirely different address format, instead of extending address space in a backwards-compatible way. Why not just append/prepend the 12 additional bytes onto existing IPv4 addresses, and write the standard such that all valid IPv4 addresses are also valid IPv6 addresses? I'm not an RFC author, but something like "All existing IPv4 addresse…

I don't think that would work. The IPv6 Notation is only the human representation. Inside the package it is a 128 bit integer. IPv4 addresses can already be put there. The problem is that everyone still needs to support a package with 128 bit addresses instead of 32 bit. There is simply no space in the IPv4 package format for the 128 bit addresses. Or anything bigger than 32 bit.

Well there is the options... But that means again every single router and host would need to support it on the path for it to be any use. So new protocol is much simpler and allows fixing other things as well.

Re: Leveraging Class E address space to mitigate IPv4 exhaustion issues in GKE

#50

Post by dangerlibrary »

dboreham wrote: post #41
dangerlibrary wrote: post #8

It never made sense to me why the authors of the IPv6 standard chose to use an entirely different address format, instead of extending address space in a backwards-compatible way. Why not just append/prepend the 12 additional bytes onto existing IPv4 addresses, and write the standard such that all valid IPv4 addresses are also valid IPv6 addresses? I'm not an RFC author, but something like "All existing IPv4 addresse…

Also, a meta-reply would be: whatever clever solution you think you've invented was surely considered. It's 30 years ago so memory fades but all this was discussed at great lengths on mailing lists and in meetings by people who knew what they were doing. The only things I don't think were envisioned at the time were: NAT prolonging the V4 space exhaustion significantly, and the level of inertia for vendors implementi…

I assure you I am under no illusions about my cleverness relative to others in this industry.
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