[routing-wg] IPv6 Routing Recommendations

Thanks for the discussion so far, there seem to be a number of 
suggestions from the emails.

First are a couple of comments that we go ahead with the document 
largely as-is.

Second is the suggestion that we should keep a figure, but try and base 
it on a bit more science than "/36 sounds better than /40."

Third is that any specific figure should be removed as it won't cover 
all cases.

The third way is easy, and if consensus went in that direction, I am 
happy to cut the /36 figure out of the document, but then I'm struggling 
to understand why we would need a separate document to RIPE-399, which 
recommends aggregation, but accepts there are reasons you may have to 
advertise more specific prefixes.  Would a modification to RIPE-399 that 
just expands on the cursory mention of "this all applies to IPv6 too," 
e.g. by adding a few IPv6 examples in the text, be sufficient?

The reason the document was originally written was that once the routing 
requirement was removed from the IPv6 address policy document, there was 
pressure for the group to come up with a number that people could put in 
filters that allowed some flexibility with announcements of more 
specific routes within their /32, with a fair chance of those prefixes 
getting propagated widely, but limited the potential for abuse.

If there is still need for a document separate to RIPE-399 (and of 
course that question is still open, but there have been some strong 
suggestions on the list that there should be), that brings us back to 
the first and second options.  The first is a simplification of the 
second, so lets think about the second.

Studying the IPv4 routing table may lead us to a potential number of 
more specific routes, but would it lead us to any conclusions about 
their length?  The Swiss example shows that the routes may not be 
subdivided from the most significant bits of the prefixes, so how do we 
do the analysis?

Remember, if this is to be a WG document, I'd like to attempt to reach 
consensus in the group (and I suspected that would never be easy), so 
all input is welcome!

Looking forward to an interesting 20 minute discussion in Prague,
Rob