Re: [Sidrops] Which 8210-bis error code should be used?

["Sriram, Kotikalapudi (Fed)" <[e-mail]>]

Oliver and I have discussed the issue off-list. Requiring an artificial insertion of an AS 0 only VAP-SPAS for the neglected AFI for the CAS is not required. The verification algorithm (hop-check function in Section 5) inherently takes care of the neglected AFI (absent VAP-SPAS) situation.

The previously proposed text change ( https://mailarchive.ietf.org/arch/msg/sidrops/C5newCanz60yBNc6myoEZfQnMoc/ ) is retracted.

But a slight modification of the paragraph in consideration would be good as follows:


OLD text:


   If, despite the above recommendations, the ASPA(s) of a CAS includes
   SPAS for one AFI but not for the other AFI (not even an AS 0), the
   ASPA SHALL NOT be rejected just for that reason.  However, such an
   ASPA(s) will be presumed to imply that the CAS has no providers
   (equivalent to AS 0 SPAS) for the AFI that they neglected to include.



NEW text:


   If, despite the above recommendations, the ASPA(s) of a CAS includes
   SPAS for one AFI but not for the other AFI (not even an AS 0), then
   for AS_PATH verification purposes, the CAS is considered to have no
   providers (i.e., absent VAP-SPAS) for the neglected AFI (see the hop-
   check function computation in Section 5).  (Note: Artificial
   insertion of an AS 0 only VAP-SPAS for the neglected AFI for the CAS
   is not required.)


The hop-check function is slightly tweaked as follows:

                             /
                             | "No Attestation" if there is no entry
                             |   in VAP-SPAS table for CAS = AS(i)
                             |
   hop(AS(i), AS(j), AFI) =  / Else, "Provider+" if a VAP-SPAS entry for
                             \   CAS = AS(i) for the mentioned AFI
                             |   is present and includes AS(j)
                             |
                             | Else, "Not Provider+"
                             \


This is basically the same function definition as before but makes it clearer that since VAP-SPAS is absent for the neglected AFI, there would be no match in the VAP-SPAS for AS(j) and hence the outcome for that AFI would be "Not Provider+".



Sriram