[db-wg] Proxy proposal large communities

On 14/11/17 23:21, Gert Doering wrote:
> Hi,
> 
> On Tue, Nov 14, 2017 at 10:12:11PM +1030, Mark Prior wrote:
>> 1. Are you planning on doing that via a script or by eye-balling the policy?
> 
> eyeballing does not scale

True but I'm somewhat amazed that you try to understand someone else's
policy anyway.

>> 2. How useful is that if their export policy is
>> 	announce { 0.0.0.0/0^0-24 } and community.contains(something)?
>>    Do you hunt for the import policies where community "something" is set?
> 
> We look for "which ASes are they going to announce, and which routes 
> originate by those".  
> 
> This fine-grained crap is something we ignore anyway (so, a tool that
> parses this and warns about non-understood extentions is ok, a tool
> that errors out is not helpful).

I would suggest it's not fine-grained crap but a sensible approach to
classify the prefix only once. If you want to know about the ASes I
might transit to you (and thus the prefixes they might announce through
me) then you should be looking for an AS set that lists them rather than
trying to "understand" a routing policy.

If that tool is building configuration that is automatically loaded onto
my routers then I don't want it to just warn about stuff it doesn't
understand. I want it to complain (bitterly) and set an error status so
I can investigate it.

Mark.