Enabling IPv6 support for IPv4-only apps on Linux

Post by wmf » Wed, Oct 04, 2023, 4:44 PM UTC

londons_explore wrote: post #111

gorkish wrote: post #108

Earlier quoted context omitted.

Yeah I agree this does seem like something that really ought to simply be configurable out of the box with options for transparently handling both 6-to-4 and 4-to-6 when the appropriate services are discoverable or configured on the network. The top level reply here discussing how MacOS handles it seems like something that should be able to be recreated with iptables, but when searching I am extremely surprised to di…

Linux is usually king when it comes to networking and configurability - so I too am really surprised it isn't an option to do something sane.

Post by hot_gril » Wed, Oct 04, 2023, 4:47 PM UTC

kuon wrote: post #96

giancarlostoro wrote: post #91

Earlier quoted context omitted.

I'm of the opinion that IPv6 is old enough that the fact we have not hopped to it yet means its not happening anytime soon. I wanted it back in 2008 when I first learned about it, and I know its older than that (90s iirc) so its either going to come one day "abruptly" by force and break half the internet, or people will do hacks to maintain IPv4 as is. I think the only way IPv6 will ever become mainstream is if eithe…

Yeah, we need more incentive. Ipv6 is harder to implement yes, it is true, there is no point in denying this and arguing it solves tons of problem (it does). Most companies have ipv4 experience and it's just simpler. There must be some political pressure to make it move. But "hopefully" the economical pressure is starting to build up, a lot of providers are cheaper in ipv6 only configuration. Still, for a company lik…

Post by p1mrx » Wed, Oct 04, 2023, 4:55 PM UTC

tsimionescu wrote: post #122

p1mrx wrote: post #105

Earlier quoted context omitted.

I think SLAAC's /64 limit functions as a "trojan horse" forcing ISPs to give everyone at least 64 bits of address space. Most would allocate /112-/128 per customer if it were slightly easier. Designing the internet with lots of unused space at the edges will probably be useful in 100 years.

Regardless of the /64 limit, I expect DHCPv6 will win out in the consumer side (with ISPs giving customers pre-configured wifi routers with DHCPv6 already configured). SLAAC is both very complicated, and its privacy extensions are anyway not something ISPs have been friendly to even if it weren't such an extra hassle.

Post by hatch_q » Wed, Oct 04, 2023, 5:14 PM UTC

lazide wrote: post #119

hatch_q wrote: post #103

Earlier quoted context omitted.

Possibly never, because security. NAT at least tries to hide insecure IoT device on your grandma's wifi. shodan.io has support for ipv6. With ipv4 you're somewhat restricted to devices that get public ip (corporate networks) or devices that drill a hole (uPnP/port forward). IPv6 devices are publicly visible by default and you need to manually setup firewall to filter this out (not trivial - especially for UDP and ICM…

Every firewall I’ve dealt with since forever has default deny on inbound traffic, state full allow for outbound connections. Regardless of NAT or not, and regardless of how cheap it is.

Post by pavel_odintsov » Wed, Oct 04, 2023, 5:24 PM UTC

photonbeam wrote: post #109

kuon wrote: post #96

Earlier quoted context omitted.

Yeah, we need more incentive. Ipv6 is harder to implement yes, it is true, there is no point in denying this and arguing it solves tons of problem (it does). Most companies have ipv4 experience and it's just simpler. There must be some political pressure to make it move. But "hopefully" the economical pressure is starting to build up, a lot of providers are cheaper in ipv6 only configuration. Still, for a company lik…

Plenty of big sites have no AAAA record even