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A comment on The world in which IPv6 was a good design (2017). Parent comment

Re:The world in which IPv6 was a good design (2017) by icedchai on Tuesday December 29, 2020 @10:08AM (#25570377)
A fully peer-to-peer network is how IPv4 worked before NAT became popular. NAT was hack to solve address shortage. I worked for a couple ISPs in the 90's and many corporate networks had fully routed addresses on their LAN. I even had this at home.
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Re:The world in which IPv6 was a good design (2017) by magicalhippo on Tuesday December 29, 2020 @10:27AM (#25570600)
I didn't have fully routed addresses on my LAN in the late 90's, because I only had dial-up.

My point is that even if I could today, with either IPv4 or IPv6, I don't really _want_ that.

It would make my internal network dependent on the external network, and the benefits don't outweigh that major downside.

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Re:The world in which IPv6 was a good design (2017) by icedchai on Tuesday December 29, 2020 @10:36AM (#25570717)
At one point I had an entire /24 routed over a 28.8K connection. I eventually upgraded to an ISDN line. Fun times.

It sounds like what you really want is a firewall, not NAT. Having a globally unique prefix (either IPv6 or v4) does not mean your network is completely accessible externally. There are no dependencies. It actually makes things simpler if you ever want to connect two internal networks.

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Re:The world in which IPv6 was a good design (2017) by magicalhippo on Tuesday December 29, 2020 @01:53PM (#25573336)
Of course I want a firewall. We all do. That much was obvious even when I was on dial-up, installing Shorewall or whatever it was back in 2000.

My point is that if you have a firewall you're in the exact same position as if you have a firewall+NAT in that you need to be able to punch holes in it.

IPv6 on its own does nothing to help with this.

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Re:The world in which IPv6 was a good design (2017) by stkdump on Tuesday December 29, 2020 @03:02PM (#25574127)
NAT make hoke punching more complicated (or depending on exact type of NAT impossible)
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Re:The world in which IPv6 was a good design (2017) by aflag on Tuesday December 29, 2020 @10:34AM (#25570683)
What is the downside? The external network only needs to know you're responsible by an IP range that your ISP gives you, you can still configure your network internally as you please.
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Re:The world in which IPv6 was a good design (2017) by magicalhippo on Tuesday December 29, 2020 @10:48AM (#25570868)
The addresses depend on the external network. If my prefix changes with IPv6, suddenly nothing works on the internal network until all the nodes are reconfigured and the firewall rules rewritten. I know because it happens to me regularly.

With NAT the internal nodes can for the most part work like normal. They might experience a gap of a few seconds where communication with the external network (the Internet) is down, but apart from that nothing.

You might say just use ULA[1]! To which I will say what's the point of IPv6 then?

[1]: https://en.wikipedia.org/wiki/Unique_local_address

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Re:The world in which IPv6 was a good design (2017) by fulafel on Wednesday December 30, 2020 @07:11AM (#25580990)
It's true that this is a problem for intermittently connected consumer networks and customers of flaky ISPs that change the prefix on you needlessly. Regulation for allocating PI space to flaky isp customers might help.
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Re:The world in which IPv6 was a good design (2017) by fulafel on Wednesday December 30, 2020 @12:58AM (#25579021)
A fully peer-to-peer network is arguably how the IPv4 internet still works, as hosts behind NAT are not really part of it. But of course it hurts the network effect when fewer users are on the network proper.
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