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Comment by Matheus28 | Hacker News Reader

Even with super long leases, couldn’t they just have a larger subnet? A /8 oughta do it.

But I guess we’re talking about the same people who made the mistake in the first place…

To steelman the choice, the reserved IP /8 subnet is 10.x.x.x and is often used for corporate networks and other larger subnets experience similar usage. People on the plane using WiFi are likely to access their corporate networks via VPN, potentially causing routing issues.

Users VPNing into the reused address space for their own home VPN are probably knowledgeable enough to figure out what is going on and a small enough user base to not care about.

Couldn't we spare a single extra /8 for airplanes to use?

Though I suppose it's not worth it when you can hit 'reboot'.

How about "we" use IPv6 instead, and nobody runs out of address space ever again?

Wouldn't this mean we have to power cycle the whole internet at the same time? Instead of supporting both which means no IPv6 in the near future

I would vote for a once a year internet holiday. It would bring minor mental wellbeing improvements, coerce important industries and systems to exercise redundancy pathways, provide opportunities to have such a cutover like switching to IPv6, and remind a million petty tyrant product managers that no, our goddamned fart app does not need 6 9s of reliability.

100 bucks says IPv6 would still not get implemented. We need legislation at this point. There's enough stubborn assholes in the networking infrastructure industry just refusing to do their job for it to happen by itself. They will insist they need to save a few thousand bucks and hold the whole damn world back.

Interestingly, there was some controversy in middle schools whereby mischievous students would deliberately disable their device's Internet access in order to play a built-in browser game, and this was seen as undesirable, so I believe that the agreed mitigation was to disable the game entirely. :-(

> just refusing to do their job

Their job is to make traffic work on the chunk of the Internet they administer. If they can do that with IPv4, they're doing the job.

If there were things unreachable by protocols other than IPv6 that people needed, that could force the issue, but there aren't.

I'm no network guy so someone please explain why using 10.x.x.x. on a plane might "potentially cause routing issues"? It doesn't jive with what I understand about unrouteable address spaces. Is the 10.x.x.x space somehow different than the 192.168.x.x space that millions of people use VPN's out of every day (basically every WFH person on their cheap NAT'd home Wifi)?

Because many of the VPNs have _their_ internal routing using 10.0.0.0/8.

If the plane network uses 10.0.0.0/8; and then the VPN you're trying to connect to uses 10.0.0.0/8, stuff breaks.

Because IPv4 sucks! If you don't have enough publicly routable addresses then you are forced to use reserved ranges like 10/8. That means you'll get collisions, ie. multiple networks using the same addresses. With IPv6 you'd just get a real public IP address and all would be fine.

Edit: I feel bad for saying IPv4 sucks. It's one of my favourite pieces of tech and an astonishingly good one at that. It just doesn't have a big enough address space.

Hopefully I'm not too late to the party. When you setup a VPN, you are telling your network stack that all connections for a set of IP addresses will be handled by it, in this example case, all 10.x.x.x requests will be routed through the VPN's application. The VPN will then wrap up all requests through that connection and send them out to the Internet towards the public IP address on the other end of the VPN. To send things out to the Internet, you use your default gateway, basically an IP address everything is sent to when it doesn't match any other configured route `ip route`. If your local network is using the 10.x.x.x subnet for local connections, it will likely be 10.0.0.1 or something. But who handles that route? Your VPN which would then just recursively keep handling its own request.

Now, I think VPN applications are smarter than that and will still get the outgoing packet to the default gateway (citation and research needed), but what happens when it doesn't know to handle a route automagically. For instance, with DHCP, a router can tell your computer what DNS server to reach out to. If that's on the local network, now you see all DNS requests actually routing into the network on the other side where you almost certainly aren't going to be talking to a DNS server. And now, you can't go to any websites.

Hopefully this helps. I'm not the most knowledgeable about VPNs and routing, but I'm pretty sure this is all fairly accurate.

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