Question about 6to4

Ted Mittelstaedt tedm at
Fri May 15 00:47:44 CEST 2009


> -----Original Message-----
> From: at 
> [ at] On 
> Behalf Of Martin List-Petersen
> Sent: Thursday, May 14, 2009 3:05 PM
> To: Ted Mittelstaedt
> Cc: ipv6-ops at
> Subject: Re: Question about 6to4
> Steve Wilcox wrote:
> > Hey Ted,
> >  you sort of answered your own question - the aggregate is 
> announced 
> > as an anycast and the v6 routing table doesn't know where the 
> > individual v6 packets are destined.
> > 
> > So the v6 packets find their way to the nearest 6to4 relay, 
> that then 
> > converts to v4 and its routed out as v4. As you say HE is one major 
> > sink for that, as a result of them being so well connected.
> > 
> > Thats one of the downsides with 6to4 - the packet may go in 
> the wrong 
> > direction in v6 before passing through the relay and then 
> heading in 
> > the opposite direction to find the v4 endpoint.
> And just to add to that, the v4 side works exactly the same. 
> The anycast prefix there is
> In our case (we're in Ireland), the relays in our path were 
> in Sweden, Germany and Italy, which never is a good result, 
> so we set our own gateway up.
> Now, talking about 6to4, 6to4 is never to be preferred. If 
> you can get people to use native IPv6, you should at any time 
> prefer that solution, or 6in4 tunnels for that sake.

The problem is finding a cheap router costing under $40 that
can be used on the end of a DSL line, and that speaks IPv6 and
is supported from the manufacturer.  Right
now what seems to be the popular route to go is the
firmware but all the routers that are in that price range are
4MB flash and will only run the mini loads, not the mega loads
(ie: Linksys WRT54GL, ASUS WL520GU, etc.) and getting IPv6 running
in 4MB on those is a lot of configuration work that I can see
is just waiting to crash and burn and create a support issue.
Going with a better router like in the $80 range is fine for the
small business customers but the residential people won't go for
that unless they are the early adopter/experimenter types.  I
really want to stay in the role of ISP providing the pipe, not
ISP providing the pipe and fixing your $40 router :-(


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