Re: [spring] [Mapping Server] Conflict Resolution

"Les Ginsberg (ginsberg)" <ginsberg@cisco.com> Fri, 17 March 2017 07:11 UTC

From: "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>
To: tech_kals Kals <tech.kals@gmail.com>, "spring@ietf.org" <spring@ietf.org>, "Peter Psenak (ppsenak)" <ppsenak@cisco.com>, "Stefano Previdi (sprevidi)" <sprevidi@cisco.com>, "martin.pilka@pantheon.tech" <martin.pilka@pantheon.tech>
Thread-Topic: [Mapping Server] Conflict Resolution
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Date: Fri, 17 Mar 2017 07:11:11 +0000
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Subject: Re: [spring] [Mapping Server] Conflict Resolution
Precedence: list

It is not possible to answer your query because the way you have presented your entries (X, E1, E2, E3) does not tell us what conflicts you have.
Do you have two SIDs assigned to the same prefix? (Prefix conflict)
Do you have the same SID assigned to two different prefixes? (SID conflict)

This matters – see Section 3.3.6 of the draft for an example as to why.

Please present your example in the form defined in Section 3:

       Prf - Preference Value (See Section 3.1)
       Pi - Initial prefix
       Pe - End prefix
       L  - Prefix length
       Lx - Maximum prefix length (32 for IPv4, 128 for IPv6)
       Si - Initial SID value
       Se - End SID value
       R  - Range value (See Note 1)
       T  - Topology
       A  - Algorithm

       A Mapping Entry is then the tuple: (Prf, Src, Pi/L, Si, R, T, A)

Thanx.

   Les


From: tech_kals Kals [mailto:tech.kals@gmail.com]
Sent: Thursday, March 16, 2017 7:22 PM
To: spring@ietf.org; Les Ginsberg (ginsberg); Peter Psenak (ppsenak); Stefano Previdi (sprevidi); martin.pilka@pantheon.tech
Subject: [Mapping Server] Conflict Resolution

Hi Experts,

  Could you please explain me what would be the expected behavior in the following scenario in Quarantine approach.

  Mapping entries E1, E2, E3 are Active entries.

  In case, if incoming new entry say X which has conflict with E1, E2 and E3.

  Assume, X is better than E1 but not better than E2.  ( E1 < X < E2)

  1] X is better than E1 so E1 will become excluded entry and X will become an active entry

  2] Now, X is compared with E2. E2 is better than X. So, X will become excluded entry and E2 is an active entry as it was.

So, X and E1 will become "excluded entry".

I couldn't find any info as shown above in the RFC. Can you please clarify ?


My doubts:
1) Will the entry become active only if it wins with all entries which are conflicted with this ?
2) When doing conflict resolution with other entries, it can win with some entries and can lose to some? What could be the behavior ?
     - This is the case which I explained above.
     - In this case, X can become active by winning to E1 and lose E2 which leads X and E1 to become inactive/excluded entry.


can you please clarify ?


Regards,
__tech.kals__

Re: [spring] [Mapping Server] Conflict Resolution Les Ginsberg (ginsberg)