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Enabling IPv6 support for IPv4-only apps on Linux

blog.apnic.net

41–50 of 199 posts

Re: Enabling IPv6 support for IPv4-only apps on Linux

#41
post #19

Earlier quoted context omitted.

What's the benefit of DHCPv6 over SLAAC (genuine question, never looked into DHCPv6 at all)

You can do finer-grained subnets with DHCP than SLAAC will give you.

As a general rule, if you're deploying IPv6 subnets sized as anything other than /64, you're doing it wrong

Re: Enabling IPv6 support for IPv4-only apps on Linux

#43

Earlier quoted context omitted.

You don't need to merge upstream! Its your source, your build, your rules.

Maintaining your own patchset for your personal use is usually not a good use of your time and expertise. Every time someone runs a linter over upstream, you're going to have to remake that patch. Sure, it's only 20 mins... But that multiplied by every bit of software you patch and every release, and you quickly realise that a huge chunk of your life was wasted doing what is effectively busywork. Instead, contribute…

You don't have to, its your own fork.

Re: Enabling IPv6 support for IPv4-only apps on Linux

#44

Earlier quoted context omitted.

You don't need to merge upstream! Its your source, your build, your rules.

Maintaining your own patchset for your personal use is usually not a good use of your time and expertise. Every time someone runs a linter over upstream, you're going to have to remake that patch. Sure, it's only 20 mins... But that multiplied by every bit of software you patch and every release, and you quickly realise that a huge chunk of your life was wasted doing what is effectively busywork. Instead, contribute…

The "upstream or nothing" attitude is an attempt to erase any difference between free software and "visible source".

Offering changes back to upstream is always encouraged, but whether or not it is accepted is largely irrelevant to the patch author.

Re: Enabling IPv6 support for IPv4-only apps on Linux

#45

The main advantage of Linux over other systems is that its available from source and thus can be patched and recompiled easily. Here we see someone using LD_PRELOAD to patch the behavior of a binary, because they rely on distributions pre-compiled packages without means to change the source code themselves. This sort of negates that advantage, right?

This way works with any binary. Your idea of patching the source would have to be done to every single program that uses the network that you want to work like this. Really this should just be a part of the OS though.

Re: Enabling IPv6 support for IPv4-only apps on Linux

#46

Super cool! I tried doing a pure IPv6 network a little over a decade ago; Maybe I’ll try it again. Though, my cheap IoT devices likely still need IPv4… but perhaps not internet connectivity. It might be fun to explore just how much IPv4 continues to be ingrained into cheap Things (eg: Arduino WiFI?) There always seems to be a long tail of small places where IPv4 pops straight back into the equation.

plus these individual devices will live for a long time. I recently had to setup a non-encrypted website because I have a few old devices that can no longer do HTTPS. IPv4 on local networks will probably exist for a very long time.

> I recently had to setup a non-encrypted website because I have a few old devices that can no longer do HTTPS.

That sounds like they haven't been updated for TLS>1.1 – if that is the case then rather than going all the way down the HTTP you could enable TLS1.1 (and maybe 1.0). It is open to POODLE/BEAST/others that way, but still have some protection and the site's configuration differs less from the rest of your infrastructure.

Unless the site is completely internal only of course, in which case just sticking with HTTP may be less faf.

Re: Enabling IPv6 support for IPv4-only apps on Linux

#48
I think retrofitting IPv4-only apps for IPv6 compatibility might be a short-term fix. It could be more forward-thinking to focus on developing new apps with inherent IPv6 support to prevent accruing technical debt and facing complications tied to maintaining outdated IPv4-only applications.

Re: Enabling IPv6 support for IPv4-only apps on Linux

#49
post #41
post #19

Earlier quoted context omitted.

You can do finer-grained subnets with DHCP than SLAAC will give you.

As a general rule, if you're deploying IPv6 subnets sized as anything other than /64, you're doing it wrong

The only reason for that "rule" is SLAAC.

Re: Enabling IPv6 support for IPv4-only apps on Linux

#50

Earlier quoted context omitted.

plus these individual devices will live for a long time. I recently had to setup a non-encrypted website because I have a few old devices that can no longer do HTTPS. IPv4 on local networks will probably exist for a very long time.

> I recently had to setup a non-encrypted website because I have a few old devices that can no longer do HTTPS. That sounds like they haven't been updated for TLS>1.1 – if that is the case then rather than going all the way down the HTTP you could enable TLS1.1 (and maybe 1.0). It is open to POODLE/BEAST/others that way, but still have some protection and the site's configuration differs less from the rest of your in…

Is there any way to get a certificate that these old devices would trust and that would work over TLS < 1.2?
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