Re: An alternative to 6to4 and teredo

[Brian E Carpenter <brian@hursley.ibm.com>]

I've never argued against tunnel brokers for isolated hosts. Please 
remember that 6to4 was actually designed for whole sites with no 
IPv6 ISP, not for isolated hosts. The fact that a well-known operating 
system ships 6to4 for isolated hosts doesn't change the original design 
point.

    Brian

Erik Nordmark wrote:
> 
> A long time ago Joshua wrote:
> 
> > This is a chicken and egg problem. That is why transition tools are
> > important. Apple could develop and ship a system that implemented 6to4
> > and shipworm/teredo to fall back on when IPv6 wasn't immediately
> > available. Apple could also ship an application that made use of IPv6.
> > Microsoft is in a similar position. Once that's done, third party
> > developers can take advantage of that, assuming all of the transition
> > mechanisms work. Shooting down 6to4 eliminates one transition
> > mechanism. Not even acknowledging Teredo is another shot at transition.
> 
> I argue that using tunnel broker and extending it to support UDP tunneling
> across NATs is much better than 6to4 and Teredo when considering the space
> of temporary solutions until the ISPs provide native IPv6.
> 
> I think tunnel brokered tunnels provide better incentives for deployment
> than 6to4 relays because they are visible to the user - the provider
> can throw in some content and adds as part of the web page you visit,
> and the can claim "we have x,000 users". A 6to4 relay provider can not
> do this. The "connect to IPv6" icon on the desktop also helps drive
> IPv6 awareness - folks will see that enabling that allows them to run
> their IPv6 peer to peer games even across an IPv4 NAT box, thus they
> are more likely to ask their ISP for native IPv6 than if this is
> completely automatic as is envisioned for Teredo.
> 
> The only downside of the tunnel broker schemes is potentially less efficient
> routing. But if the services are popular this might be a self-correcting
> problem. And if they are not popular it is either because there is sufficient
> native IPv6 access or that IPv6 is not being widely used.
> 
> The upsides for tunnel broker (with UDP tunneling across NATs, or even PPP
> over  TCP over NATs for those so inclined) in addition to the incentives above
> is that it avoids the security issues around 6to4 and Teredo, and is
> operationally much much simpler to trouble-shoot.
> And there isn't any risk of creating separate IPv6 native and 6to4
> universes since it is all IPv6 native addresses with regular IPv6 routing.
> 
>   Erik