As soon as we get to about 70%, I reckon some games and apps will stop supporting ipv4 on the basis that nat traversal is a pain and dual stack networking is a pain.
If you spend 2 days vibe coding some chat app and then you have to spend 2 further days debugging why file sharing doesn't work for ipv4 users behind nat, you might just say it isn't supported for people whose ISP's use 'older technology'.
After that, I reckon the transition will speed up a lot.
> some games and apps will stop supporting ipv4 on the basis that nat traversal is a pain and dual stack networking is a pain
None of these are actually the game/app developers' problem. The OS takes care of them for you (you may need code for e2e connectivity when both are behind a NAT, but STUN/TURN/whatever we do nowadays is trivial to implement).
NAT traversal not needed. Just need to deal with firewalls. So that's one fewer thing to think about when doing peer-to-peer file sharing over the internet.
No. Here's a simple strategy: the two peers send each other a few packets simultaneously, then the firewall will open because by default almost all firewalls allow response traffic. IPv6 simplifies things because you know exactly what address to send to.
And yet here I am, fighting with our commercial grade fiber ISP over obscure problems in their IPv6 stack related to MTU and the phase of the moon. Sigh.
I've been at this on and off for about a year (it's not a high priority thing, more of a hobby).
~$ host gmail.com
gmail.com has address 142.250.69.69
gmail.com has IPv6 address 2607:f8b0:4020:801::2005
gmail.com mail is handled by 10 alt1.gmail-smtp-in.l.google.com.
gmail.com mail is handled by 30 alt3.gmail-smtp-in.l.google.com.
gmail.com mail is handled by 5 gmail-smtp-in.l.google.com.
gmail.com mail is handled by 20 alt2.gmail-smtp-in.l.google.com.
gmail.com mail is handled by 40 alt4.gmail-smtp-in.l.google.com.
~$ host gmail-smtp-in.l.google.com.
gmail-smtp-in.l.google.com has address 142.250.31.26
gmail-smtp-in.l.google.com has IPv6 address 2607:f8b0:4004:c21::1a
If you spend 2 days vibe coding some chat app and then you have to spend 2 further days debugging why file sharing doesn't work for ipv4 users behind nat, you might just say it isn't supported for people whose ISP's use 'older technology'.
After that, I reckon the transition will speed up a lot.