What is BCP re De-Aggregation: strict filtering /48s out of /32 RIR minimums.

Wed Nov 14 23:31:44 UTC 2012

On Nov 14, 2012, at 1:50 PM, William Herrin <bill at herrin.us> wrote:

> On Wed, Nov 14, 2012 at 3:10 PM, Michael Smith <mksmith at mac.com> wrote:
>> I guess I'm confused.  I have a /32 that I have broken up
>> into /47's for my discrete POP locations.  I don't have a
>> network between them, by design.  And, I won't
>> announce the /32 covering route because there is
>> no single POP that can take requests for the entire
>> /32 - think regionalized anycast.
>> 
>> So, how is it "worse" to announce the deaggregated
>> /47's versus getting a /32 for every POP?  In either
>> case, I'm going to put the same number of routes into the DFZ.
> 
> Hi Michael,
> 
> If you announce an ISP /32 from each POP (or an end-user /48, /47,
> etc) then I know that a neutral third party has vetted your proposed
> network configuration and confirmed that the routes are disaggregated
> because the network architecture requires it. If you announce a /47
> from your ISP space, for all I know you're trying to tweak utilization
> on your ISP uplinks.
> 
Again, I thought the discussion was about PI, not PA.  I don't announce any PA.

> In the former case, the protocols are capable of what they're capable
> of. Discrete multihomed network, discrete announcement. Like it or
> lump it.
> 
> In the latter case, I don't particularly need to burn resources on my
> router half a world away to facilitate your traffic tweaking. Let the
> ISPs you're paying for the privilege carry your more-specifics.
> 

You have great confidence in the immutability of design and the description thereof.

Mike