RE: [RRG] Geographic aggregation-based routing is at odds with reality

["Tony Li" <tony.li@tony.li>]

Hi Iljitsch,
 

|If I want to shrink my routing tables I can filter out any Canadian  
|more specifics all over the world except in Canada, and 
|instead put in  
|an aggregate that covers the address space used in Canada.


True, but if you do that unilaterally, you affect the flow of traffic as
most specifcs draw the traffic around your network, and you incur the phone
calls from Canada, who will kindly ask you to cease and desist, eh?  ;-)

We discovered this when we tried to do proxy aggregation the first time: the
abstraction action boundary MUST be carefully and thoughtfully engineered to
avoid unintended consequences.  This requires cooperation.


|If you are also a large network with customers in Canada, I 
|don't care  
|whether you also implement this aggregation or not. I can either do  
|hot potato and give you the Canadian traffic close to the source and  
|thus optimize for traffic flow, or filter those more specific,  
|transport the traffic to Canada and then give it to you, optimizing  
|for routing table size.


Almost every carrier operates with hot potato in mind, out of vested
self-interest.

Tony


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