Re: 6to4 tunnel trouble
Mike Crowe wrote:
On Sun, Dec 07, 2008 at 12:42:45AM +0100, Pascal Hambourg wrote:
www.kame.net seems to be unreachable from a 6to4 host,
Is it expected that arbitrary hosts with IPv6 addresses should be able
to find a way of getting packets back to 6to4 addresses?
That is corect, yes. In a perfect world that would be the case.
But not every provider has a 6to4 gateway and not every provider is
ready for IPv6. On top of that, the different providers apply filtering
on what they accept on their BGP session and what not. Some do this
based on the whois databases, which means 2002::/16 and 192.88.99.0/24
will be filtered out crossing from provider to another unless otherwise
agreed.
This is both positive and negative. It means that not anybody actually
has a route to a 6to4 gateway (or the opposite path).
If so, then there would appear to be a fault somewhere between
www.kame.net and me (and you).
A fault with kame is not unlikely. Sometimes things break in the
internet. A lot more often in IPv6 than in IPv4, because a lot of the
carriers and provider don't take is serious, yet. I have for example one
transit provider, that doesn't give us an SLA on IPv6, because they
themselfes only have one transit provider with IPv6. That has in the
past caused things to break for longer than you'd expect (as in days).
Ever since, we've obviously ensured, that it can't happen to us anymore
(hopefully) :)
If not, then 6to4 would seem to be rather useless. :(
Anyway, thanks for all the responses. I shall investigate the
recommended tunnel brokers.
The successrate is higher with a tunnel, because there is a clear
defined end-point to you.
With 6to4 the traffic flows encapsulated to the first known 6to4 gateway
in your path. The return-traffic flows to the first known 6to4 gateway
in your destinations path. And they are nearly always different. So if
one is broken, traffic doesn't flow.
With a tunnel the traffic always originates and returns to your
tunnelprovider over the same tunnel-server.
Kind regards,
Martin List-Petersen
--
Communication is the beginning of understanding
-- AT&T
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