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

[Keith Moore <moore@cs.utk.edu>]

> > I use 6to4 on hosts every day, so I don't consider it hammering.
> >
> > But 6to4 was primariliy intended for routers.  That it happens
> > to work on some hosts is a happy side-benefit, not the design goal.
> >
> > Keith
> 
> If you want to run 6to4 on a host that happens to have a global IPv4 address
> and can accept 'ip-proto-41' w/o creating a security risk, then that is fine.
> But (and you seem to recognize this), if one wants to postulate a "generalized
> host-based 6to4" mechanism, that is a different matter and one that is not
> covered by any existing RFCs.
> 
> To realize a "generalized host-based 6to4", one would need to incorporate the
> NAT traversal mechanisms first pioneered by TEREDO and the two-stage (end-to-edge;
> edge-to-internet) tunneling mechanism first pioneered by ISATAP. 

No, that's not "generalized host-based 6to4", that's "6to4 trying to accomodate
NAT brain-damage".  A solution which works well (okay, as well as possible) in 
the presence of NATs will be very sub-optimal between hosts whose communications
is not hampered by NAT.  Which is why something like 6to4 and something like 
Teredo are both needed. 

Keith