Re: Communities

[Geoff Huston <gih () telstra net>]

Jeffrey Haas wrote:
> draft-bonaventure-bgp-redistribution-01
>
> This draft included:
> IDRP style DIST_LIST_INCL, DIST_LIST_EXCL
> Proxied NO_EXPORT
> Proxied Prepending
>
> The IDRP-style DIST_LISTs seem to generate most of the heat.  We never
> got a firm feel for why the other two componenents were disliked.
>
> Geoff Huston proposed draft-huston-nopeer-00.txt to attempt to address
> some of the route propagation issues that the DIST_LISTs were intended
> to address.


The problem, as I saw it, was that in attempting to specify a subset of
the routing space the authors specified an enumerated list of AS's that formed
the boundary of this subset. The two major problems, as I see it, is that you may not
have up to date information about what As's are on the boundary of the subset
which you want to apply to the redistribution, and each remote AS that is not
on the boundary has no knowledge whether it is intended to be inside or outside
this set.

The alternative approach was to specify a common condition which characterized 
all members of the subset, allowing each remote AS to use local knowledge to see
if it met the originator-defined constraints or not. This was the basis of the
no-peer approach.

 Geoff Huston
 Telstra