[Idr] Keyur's question -- draft-sriram-idr-route-leak-detection-mitigation

["Sriram, Kotikalapudi" <[e-mail]>]

Posting this message on the list per Sue’s request.

Keyur asked a question about the proposed solution at the mike during my presentation yesterday.
I spoke with him afterwards to fully understand his question/suggestion.
As I understand now, his question is: Is it possible to augment your route-leak solution 
with another solution that is based on AS path filtering? 
This should be especially easy for ISPs that have only stub AS customers. 

My answer: Using a combination of different approaches makes sense. 
Also, in cases when the ISP has a complete and accurate view of its customer cone (CC), then also
the AS path filtering can be applied for the set of ASes in the CC (by the ISP’s customer facing routers). 
The draft does present a stopgap solution in the form of construction of 
a customer-cone prefix filter list from ROAs (when RPKI is in a mature state).
For ISPs to have an accurate picture of their CCs is easier when closer to the edges of the Internet, 
but much harder for the ISPs in the middle or at the top.
  
Keyur also mentioned about the possibility of augmenting the RLP indicator based proposal with 
the use of AS path based Outbound Router Filter (ORF). This needs further discussion.

Sriram