Anybody behind a NAT64?

[Daniel Roesen]

On Fri, Dec 07, 2012 at 11:57:48AM +0100, Tore Anderson wrote:
> Mhm. Most mobile providers here assigns their customers public IPv4
> addresses, so use of DNS64 in a dual-stack setup would take the traffic
> through a NAT instance it could have avoided. Not optimal.

Bingo. It's the same problem space for residential fixed line CPEs...
where you want to offer dual-stack to the customer LAN, but also support
IPv6-only endpoints in this LAN via NAT64/DNS64.

> That said, I'm expecting that due to IPv4 exhaustion, most of the
> providers will eventually have to switch to private IPv4 addresses +
> CGN. When that happens, avoiding DNS64 doesn't really matter all that
> much anymore, since all the IPv4-destined traffic will have to pass
> through a NAT instance either way.

Well, it avoids the inherent problem of translation between incompatible
addressing systems - see all the NAT64 failure cases.

With "DNS64 desired" signalling, you could avoid NAT64 problems for
IPv4-capable clients while at the same time support IPv6-only clients
via NAT64.

Best regards,
Daniel

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