Re: 6to4 relays [Re: WG Review: IPv6 Operations (v6ops)]

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

Rob Austein wrote:
> 
> At Wed, 11 Sep 2002 03:59:41 -0700, Randy Bush wrote:
> >
> > >> We are still missing an RFC really analysing host-based 6to4,
> > >> and until that work has been done we don't know what is bogus.
> > > a new work item for the v6ops WG?
> >
> > how is this different from what shipworm is trying to solve?
> 
> Shipworm has a lower required density of global IPv4 addresses;
> host-based-6to4 has less reliance on middleboxes.

Also (this is what Jim's reply was getting at too), 6to4 assumes
that it is implemented *in* a router (or NAT/router) whereas Teredo
assumes it has to traverse an uncooperative NAT.

6to4 simply fails if it is *behind* a NAT. It wasn't aimed
at that scenario. It wasn't designed as a host solution, so
NAT traversal was not a requirement. So when you hammer 6to4
into a host, there are cases where it simply cannot work.

   Brian

     Brian