V6 still not supported

Philip Homburg pch-nanog-2 at u-1.phicoh.com
Sat Mar 26 11:24:17 UTC 2022

>The only far ressemblance with 6to4 is the thing that was actually nice in the
> design, the automatic word in automatic tunnel. Which for the rest of us mean
>s stateless. Compared to CGNATs that is huge.

Any form of communication with the current IPv4 internet requires some
sort of CGNAT. We no longer have enough IPv4 addresses to give each customer
an unique one. So some ISPs are forced to map multiple customers to a
single IPv4 address. Which results in CGNAT. Technically, A+P (address
plus port) mapping is a bit different, but for the customer that doesn't
make a lot of difference. And A+P has serious scalability problems.

>Beyond that the proposal is not a tunnel and more akin to a nat64 since it all
>ows v6 nodes to talk to v4 nodes. The network can be pure v4 or pure v6 if the
> method is implemented as a bump in the stack at the wrong end.

You mostly ignored the routing problems I brought up. With NAT64 each ISP
is in full control over all routing. Your problem has routing aspects
that are not under control of the ISP. 

>Your response is also missing the capability to extend the IPv4 network a mill
>ion times. Or drop it completely while maintaining IPv4 applications.

Extending IPv4 is fine (except for the installed base of IPv6). It is not fine
if the extension leads to problem in other areas, like routing.

There are other problems to consider. For example, IPv6 can be added 
transparently to a network with legacy IPv4-only hosts. Hosts can get a 
public IPv6 address and a RFC 1918 IPv4 address. I wonder how in your
approach such a mix of legacy and new hosts will work out.

>6to4 was meant for early v6 to interconnect islands. A solution for a problem 
>that never really existed. Solutions without a problem aren?t usually popular.

We seem to have a different recall of history. 6to4 was extremely popular.
Popular enough that major content providers did not turn on IPv6 until
host stacks were modified to essentially kill 6to4. (in case we are talking
about different 6to4 protocols. I meant the one that interconnects with the
non-6to4 IPv6 internet. So more than just islands)

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