On Jun 14, 2011, at 2:36 PM, Joel Jaeggli wrote:
On Jun 14, 2011, at 11:16 AM, Tony Hain wrote:
Keith is correct, and the further issue is that the *-only-* reason the
'poorly managed' relays are in the path is that the content providers are
refusing to deploy the matching 6to4 router that would take a direct
connection from the customer.
6to4 direct between the content and consumer is still an 'unmanaged' tunnel
which takes exactly the same path as IPv4 would, so the 'badness' is not due
to managed vs. not.
And the breakage still exists even if you do that.
As I understand it, the breakage mostly happens when the traffic doesn't take
exactly the same path as IPv4 would, but rather when the traffic moves between
the IPv4 world and the IPv6 world (or vice versa) via a relay router that's
advertising a route to a network that it can't actually get traffic to.
Though of course there are other sources of breakage: ISPs that filter
protocol 41 (thus violating the "best effort" model); and NATs, including LSNs.
Neither of these is 6to4's fault. The IPv4 network is supposed to make a best
effort to convey traffic from source to destination, regardless of protocol
type, without altering it other than the TTL field. If ISPs break 6to4
traffic by filtering protocol 41, that's clearly their fault. Likewise, if
ISPs break 6to4 traffic by imposing NAT on their customers, that's also quite
clearly their fault. It's not like we haven't known FOR TWENTY YEARS NOW
(remember Kobe?) that the Internet was running out of addresses and had a
standardized replacement in place FOR OVER FIFTEEN YEARS.
If an ISP that has aggressively deployed IPv6 wants to whine about 6to4 support
issues, I guess they have a legitimate gripe.
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