On Nov 14, 2012, at 1:50 PM, William Herrin <bill@herrin.us> wrote:
On Wed, Nov 14, 2012 at 3:10 PM, Michael Smith <mksmith@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