[6bone] RFC2772 rewrite -- bigger scope goals

[Robert Kiessling]

Here is a rather radical proposal:

        Peerings between 6bone sites MUST NOT carry any other routes apart 
        from 3FFE and a summary route for 2001/3.

This achieves a number of goals:

- it provides a clear distinction between the experimental part from the rest of 
  the IPv6 world

- interconnections between 6bone and the rest of the IPv6 world can still 
  be numerous and reliable

- existing services in the 3FFE space can be accessed from everywhere, 
  noone is cut off

- cost-free trial implementation is still possible, but transition to RIR space
  is encouraged

- since RIR sites can filter RIR space from peerings with 6bone sites,
  BGP problems from 6bone sites will not affect the global network

and last but not least

- it's a very simple, verifyable criterion

Of course, all is not gold, so there are some drawbacks:

- 6bone sites will no longer see 2001 routes, so they will need to do 
  "closest exit" routing to the nearest RIR site.

- peerings between dual (RIR & 6bone) sites will not carry 2001 space

- propably others I haven't thought of

Robert