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bigcityslider • last Sunday at 11:02 PM • 1 reply • view on HN

6to4 or NAT64 isn't the same thing as what all those IPv4+/5/7/8 people want, if that's what you were referring to. You don't actually own the IPv4-mapped-V6 address, as in packets don't get routed to you, they go to a relay that was notoriously flaky.

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throw0101d • last Monday at 12:29 PM

> You don't actually own the IPv4-mapped-V6 address, as in packets don't get routed to you, they go to a relay that was notoriously flaky.

6to4 is exactly ownership:

> For any 32-bit global IPv4 address that is assigned to a host, a 48-bit 6to4 IPv6 prefix can be constructed for use by that host (and if applicable the network behind it) by appending the IPv4 address to 2002::/16.

> For example, the global IPv4 address 192.0.2.4 has the corresponding 6to4 prefix 2002:c000:0204::/48. This gives a prefix length of 48 bits, which leaves room for a 16-bit subnet field and 64 bit host addresses within the subnets.

* https://en.wikipedia.org/wiki/6to4

The relaying is a necessity:

              OLD    DUAL   NEW     
            ----------------------
        OLD |  32  |  32  |  XX  |      
            |------|------|------|
       DUAL |  32  |  64  |  64  |
            |------|------|------|
        NEW |  XX  |  64  |  64  |
            ----------------------
* https://github.com/becarpenter/book6/blob/main/01.%20Introdu...

There's no way around it: a non-IPng-having node will have to go through a translation box of some kind.

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