On Thu, Mar 05, 2015 at 02:39:00PM +0000, Acee Lindem (acee) wrote:
| 
| 
| On 2/24/15, 11:00 AM, "Hannes Gredler" <[email protected]> wrote:
| 
| >On Tue, Feb 24, 2015 at 03:35:11PM +0000, Acee Lindem (acee) wrote:
| >| Hannes - I don¹t see how you can jump to this conclusion - pretty lame
| >;^)
| >| Having the ability to enable or disable fast reroute protection by
| >address
| >| family by no means favors one address family over the other. There just
| >| may be deployments where protection is just not desired for both and it
| >is
| >| not like it comes for free (since you must account for the topologies
| >| being non-congruent).
| >
| >my point is that controlling LFA on a per-topology basis makes perfect
| >sense.
| >(as per your example above (non-congruent topologies), to save some
| >number crunching).
| >
| >what does not make sense is: consider we've deployed IPv4/IPv6 in the
| >default
| >topology (integrated IS-IS model) - to turn off LFA for V6 routes.
| >
| >you have done already the number crunching, so why would you want
| >to make IPv6 routes a second class citizen here ? -
| >
| >can you highlight the use-case here ?
| 
| One use case would be is that you are using IPv6 for business critical
| services that require IP FRR protection. IPv4 is being used for in-band
| network management and no protection is necessary.

again, arguing about the "usefulness" "not necessary". - what practical harm 
does it do ?

| >| On 2/24/15, 10:03 AM, "Hannes Gredler" <[email protected]> wrote:
| >| 
| >| >HG> that IPv6 is less critical than IPv4 ? -
| >| >    the IESG review will be a lot of fun then - i'll make some popcorn
| >...
| >| >
| >| >On Mon, Feb 23, 2015 at 06:26:15PM +0000, Acee Lindem (acee) wrote:
| >| >|    I agree with Les.
| >| >|    Acee
| >| >|    From: "Les Ginsberg (ginsberg)" <[1][email protected]>
| >| >|    Date: Monday, February 23, 2015 at 10:55 AM
| >| >|    To: Stephane Litkowski <[2][email protected]>,
| >Pushpasis
| >| >|    Sarkar <[3][email protected]>, Jeff Tantsura
| >| >|    <[4][email protected]>, Routing WG <[5][email protected]>
| >| >|    Subject: RE: LFA manageability : per AF config => feedback
| >required
| >| >| 
| >| >|      Stephane ­
| >| >| 
| >| >| 
| >| >| 
| >| >|      I can imagine cases in which the per AF enabling might make
| >sense
| >| >(e.g.
| >| >|      when the network associated w one address family is deemed
| >| >|      non-critical).
| >| >| 
| >| >| 
| >| >| 
| >| >|      Section 5.1 is a SHOULD ­ as is most of the document. It is
| >| >therefore
| >| >|      a suggestion as to what an implementation should provide. If a
| >| >given
| >| >|      implementer thinks this is either too onerous or not useful they
| >| >can
| >| >|      omit it w/o being in violation. But I see no reason to eliminate
| >| >this
| >| >|      ­ and in actual practice I would expect the cost of supporting
| >| >such a
| >| >|      knob to be low cost. It is hard for me to see this as
| >| >controversial.
| >| >| 
| >| >| 
| >| >| 
| >| >|         Les
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >|      From: [6][email protected]
| >| >|      [[7]mailto:[email protected]]
| >| >|      Sent: Sunday, February 22, 2015 11:10 PM
| >| >|      To: Les Ginsberg (ginsberg); Pushpasis Sarkar; Jeff Tantsura;
| >| >|      [8][email protected]
| >| >|      Subject: RE: LFA manageability : per AF config => feedback
| >required
| >| >| 
| >| >| 
| >| >| 
| >| >|      [Les:] I think your point here is that the LFA calculation is AF
| >| >|      independent within a given topology ­ but resources are consumed
| >| >|      independent of how many computations are required- giving an
| >| >operator
| >| >|      the ability to determine which prefixes are most critical seems
| >| >useful.
| >| >|      That could be per AF or per prefix.
| >| >| 
| >| >| 
| >| >| 
| >| >|      [SLI] Agree but is the ³resource saving² point strong enough to
| >| >|      mandate per AF activation ?
| >| >| 
| >| >| 
| >| >| 
| >| >|      From: Les Ginsberg (ginsberg) [[9]mailto:[email protected]]
| >| >|      Sent: Monday, February 23, 2015 05:01
| >| >|      To: Pushpasis Sarkar; Jeff Tantsura; LITKOWSKI Stephane
| >SCE/IBNF;
| >| >|      [10][email protected]
| >| >|      Subject: RE: LFA manageability : per AF config => feedback
| >required
| >| >| 
| >| >| 
| >| >| 
| >| >|      Pushpassis -
| >| >| 
| >| >| 
| >| >| 
| >| >|      From: rtgwg [[11]mailto:[email protected]] On Behalf Of
| >| >Pushpasis
| >| >|      Sarkar
| >| >|      Sent: Friday, February 20, 2015 3:28 AM
| >| >|      To: Jeff Tantsura; [12][email protected];
| >| >[13][email protected]
| >| >|      Subject: Re: LFA manageability : per AF config => feedback
| >required
| >| >| 
| >| >| 
| >| >| 
| >| >|      HI Jeff et al,
| >| >| 
| >| >| 
| >| >| 
| >| >|      I can think of a reason to have a knob per-level(or per-area) or
| >| >per
| >| >|      ISIS topology(note in ISIS a topology in ISIS always corresponds
| >| >to a
| >| >|      single AF,)
| >| >| 
| >| >| 
| >| >| 
| >| >|      [Les:] This is a common mistake to make. If one simply uses RFC
| >| >5308,
| >| >|      then IPv6 prefixes can be advertised in the same topology as
| >IPv4
| >| >(MTID
| >| >|      #0) ­ and there are implementations which support this. More
| >| >|      generally, from the protocol¹s POV a given topology can support
| >any
| >| >|      combinations of address families. It is only a convention
| >because
| >| >of the
| >| >|      reserved MTIDs specified in RFC 5120 that certain MTIDs are
| >³IPv6
| >| >|      only². But if one looks at the protocol capabilities such a
| >| >|      restriction does not exist in general.
| >| >| 
| >| >| 
| >| >| 
| >| >|      Interestingly you contradicted yourself below. J
| >| >| 
| >| >|      But I did want to set the record straight on this point ­
| >| >hopefully we
| >| >|      are in agreement.
| >| >| 
| >| >| 
| >| >| 
| >| >|      and per realm and topology in OSPF. But I cannot think of a
| >reason
| >| >of
| >| >|      why within the same topology we need another set of knobs for
| >each
| >| >AF.
| >| >|      Here, by AF I understand IPV4 or IPv6.
| >| >| 
| >| >| 
| >| >| 
| >| >|      When both IPV4 and IPV6 are part of the same IGP topology, there
| >| >is only
| >| >|      one set of backup computations needed to protect both IPV4 and
| >IPv6
| >| >|      traffic.
| >| >| 
| >| >| 
| >| >| 
| >| >|      Also I cannot think of any motivation for an operator to turn on
| >| >|      protection on only one AF and does not want to turn on for the
| >| >other
| >| >|      even if both AFs has been deployed for normal forwarding.
| >| >| 
| >| >| 
| >| >| 
| >| >|      [Les:] I think your point here is that the LFA calculation is AF
| >| >|      independent within a given topology ­ but resources are consumed
| >| >|      independent of how many computations are required- giving an
| >| >operator
| >| >|      the ability to determine which prefixes are most critical seems
| >| >useful.
| >| >|      That could be per AF or per prefix.
| >| >| 
| >| >| 
| >| >| 
| >| >|         Les
| >| >| 
| >| >| 
| >| >| 
| >| >|      Thanks
| >| >| 
| >| >|      -Pushpasis
| >| >| 
| >| >| 
| >| >| 
| >| >|      From: Jeff Tantsura <[14][email protected]>
| >| >|      Date: Friday, February 20, 2015 at 12:59 PM
| >| >|      To: "[15][email protected]"
| >| >|      <[16][email protected]>, "[17][email protected]"
| >| >|      <[18][email protected]>
| >| >|      Subject: Re: LFA manageability : per AF config => feedback
| >required
| >| >| 
| >| >| 
| >| >| 
| >| >|      Hi Stephane,
| >| >| 
| >| >| 
| >| >| 
| >| >|      /chair hat off
| >| >| 
| >| >| 
| >| >| 
| >| >|      IMO in disjoined topologies one should have flexibility to
| >| >|      enable/disable LFA as per AF.
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >|      Cheers,
| >| >| 
| >| >|      Jeff
| >| >| 
| >| >| 
| >| >| 
| >| >|      From: "[19][email protected]"
| >| >|      <[20][email protected]>
| >| >|      Date: Thursday, February 19, 2015 at 11:21 PM
| >| >|      To: "[21][email protected]" <[22][email protected]>
| >| >|      Subject: LFA manageability : per AF config => feedback required
| >| >| 
| >| >| 
| >| >| 
| >| >|        Hi Folks,
| >| >| 
| >| >| 
| >| >| 
| >| >|        As you know, LFA manageability draft is in final phasis
| >| >| 
| >| >|        The current document states per AF granularity activation as a
| >| >SHOULD.
| >| >| 
| >| >|        ³
| >| >| 
| >| >|   [23]5.1.  LFA enabling/disabling scope
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >|     The granularity of LFA activation should be controlled (as
| >alternate
| >| >| 
| >| >|     nexthop consume memory in forwarding plane).
| >| >| 
| >| >| 
| >| >| 
| >| >|     An implementation of LFA SHOULD allow its activation with the
| >| >| 
| >| >|     following criteria:
| >| >| 
| >| >| 
| >| >| 
| >| >|     o  Per address-family : ipv4 unicast, ipv6 unicast, LDP IPv4
| >| >unicast,
| >| >| 
| >| >|        LDP IPv6 unicast ...
| >| >| 
| >| >| 
| >| >| 
| >| >|     o  Per routing context : VRF, virtual/logical router, global
| >routing
| >| >| 
| >| >|        table, ...
| >| >| 
| >| >| 
| >| >| 
| >| >|        ³
| >| >| 
| >| >| 
| >| >| 
| >| >|        In the framework of ISIS/OSPF yang modelization, we are
| >| >challenging
| >| >|        this statement, do we really need to force implementation to
| >| >support
| >| >|        this ³per AF² granularity ?
| >| >| 
| >| >| 
| >| >| 
| >| >|        Please provide as soon as possible your feedback on this and
| >also
| >| >|        provide clear drivers to support or not per AF activation of
| >LFA.
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >|        Thanks for your help !
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >|        [24]Orange logo
| >| >| 
| >| >| 
| >| >| 
| >| >|        Stephane Litkowski
| >| >|        Network Architect
| >| >|        Orange/SCE/EQUANT/IBNF/ENDD/NDE
| >| >| 
| >| >|        Orange Expert Future Networks
| >| >| 
| >| >|        phone: [25]+33 2 23 28 49 83
| >| >|        mobile: [26]+33 6 37 86 97 52
| >| >|        [27][email protected]
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >| 
| >| >|  
| >| 
| >>_________________________________________________________________________
| >>_
| >| >_______________________________________________
| >| >| 
| >| >| 
| >| >| 
| >| >|  Ce message et ses pieces jointes peuvent contenir des informations
| >| >confidentielles ou privilegiees et ne doivent donc
| >| >| 
| >| >|  pas etre diffuses, exploites ou copies sans autorisation. Si vous
| >avez
| >| >recu ce message par erreur, veuillez le signaler
| >| >| 
| >| >|  a l'expediteur et le detruire ainsi que les pieces jointes. Les
| >| >messages electroniques etant susceptibles d'alteration,
| >| >| 
| >| >|  Orange decline toute responsabilite si ce message a ete altere,
| >| >deforme ou falsifie. Merci.
| >| >| 
| >| >| 
| >| >| 
| >| >|  This message and its attachments may contain confidential or
| >| >privileged information that may be protected by law;
| >| >| 
| >| >|  they should not be distributed, used or copied without
| >authorisation.
| >| >| 
| >| >|  If you have received this email in error, please notify the sender
| >and
| >| >delete this message and its attachments.
| >| >| 
| >| >|  As emails may be altered, Orange is not liable for messages that
| >have
| >| >been modified, changed or falsified.
| >| >| 
| >| >|  Thank you.
| >| >| 
| >| >|  
| >| 
| >>_________________________________________________________________________
| >>_
| >| >_______________________________________________
| >| >| 
| >| >| 
| >| >| 
| >| >|  Ce message et ses pieces jointes peuvent contenir des informations
| >| >confidentielles ou privilegiees et ne doivent donc
| >| >| 
| >| >|  pas etre diffuses, exploites ou copies sans autorisation. Si vous
| >avez
| >| >recu ce message par erreur, veuillez le signaler
| >| >| 
| >| >|  a l'expediteur et le detruire ainsi que les pieces jointes. Les
| >| >messages electroniques etant susceptibles d'alteration,
| >| >| 
| >| >|  Orange decline toute responsabilite si ce message a ete altere,
| >| >deforme ou falsifie. Merci.
| >| >| 
| >| >| 
| >| >| 
| >| >|  This message and its attachments may contain confidential or
| >| >privileged information that may be protected by law;
| >| >| 
| >| >|  they should not be distributed, used or copied without
| >authorisation.
| >| >| 
| >| >|  If you have received this email in error, please notify the sender
| >and
| >| >delete this message and its attachments.
| >| >| 
| >| >|  As emails may be altered, Orange is not liable for messages that
| >have
| >| >been modified, changed or falsified.
| >| >| 
| >| >|  Thank you.
| >| >| 
| >| >| References
| >| >| 
| >| >|    Visible links
| >| >|    1. mailto:[email protected]
| >| >|    2. mailto:[email protected]
| >| >|    3. mailto:[email protected]
| >| >|    4. mailto:[email protected]
| >| >|    5. mailto:[email protected]
| >| >|    6. mailto:[email protected]
| >| >|    7. mailto:[email protected]
| >| >|    8. mailto:[email protected]
| >| >|    9. mailto:[email protected]
| >| >|   10. mailto:[email protected]
| >| >|   11. mailto:[email protected]
| >| >|   12. mailto:[email protected]
| >| >|   13. mailto:[email protected]
| >| >|   14. mailto:[email protected]
| >| >|   15. mailto:[email protected]
| >| >|   16. mailto:[email protected]
| >| >|   17. mailto:[email protected]
| >| >|   18. mailto:[email protected]
| >| >|   19. mailto:[email protected]
| >| >|   20. mailto:[email protected]
| >| >|   21. mailto:[email protected]
| >| >|   22. mailto:[email protected]
| >| >|   23. 
| >| 
| >>https://tools.ietf.org/html/draft-ietf-rtgwg-lfa-manageability-07#section
| >>-
| >| >5.1
| >| >|   24. http://www.orange.com/
| >| >|   25. 
| >| 
| >>https://monsi.sso.francetelecom.fr/index.asp?target=http%3A%2F%2Fclicvoic
| >>e
| >| 
| >>.sso.francetelecom.fr%2FClicvoiceV2%2FToolBar.do%3Faction%3Ddefault%26roo
| >>t
| >| >service%3DSIGNATURE%26to%3D+33%202%2023%2028%2049%2083%20
| >| >|   26. 
| >| 
| >>https://monsi.sso.francetelecom.fr/index.asp?target=http%3A%2F%2Fclicvoic
| >>e
| >| 
| >>.sso.francetelecom.fr%2FClicvoiceV2%2FToolBar.do%3Faction%3Ddefault%26roo
| >>t
| >| >service%3DSIGNATURE%26to%3D+33%206%2037%2086%2097%2052%20
| >| >|   27. mailto:[email protected]
| >| >
| >| >
| >| >| _______________________________________________
| >| >| rtgwg mailing list
| >| >| [email protected]
| >| >| https://www.ietf.org/mailman/listinfo/rtgwg
| >| >
| >| 
| 

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