[Idr] Shepherd's review of draft-ietf-idr-bgp-bfd-strict-mode-13.txt

[Susan Hares <[e-mail]>]

Jeff:

The general concepts of the BFD strict state machine are excellent.

Changes needed prior to WG LC

  1.  Needs to denote TBD-X and TBD-Y as unique values



The BGP session attributes need values (TBD-X) as TBD-X1, TBD-X2, ... TBD-X5.

The BGP events needs to have  values (TBD-Y) as TBD-Y1...



I suspect you were planning to do this in the final edit.


  1.  Events that may require BfdEnable and BfdSTrictEnabled


  *   Event TBD-Y1 BfdAdminDown - does this need BfdStrictEnabled as Optional Attribute?
     *   If BfdStrictEnabled is not TRUE, what does it mean?



  *   Event TBD-Y2 BfdDown - does this
     *   Should BfdEnabled be set? If yes, please add.  If no, why not?
     *   What happens if BfdStrictEnabled is FALSE?
     *   What happens if BfdStrictEnabled is TRUE?



  *   Event TBD-Y3 BfdUp
     *   What happens if BfdStrictEnabled is FALSE?
     *   What happens if BfdStrictEnabled is TRUE?
     *   It is unclear how BfdStrictEnable interacts.
  *   Event TBD-Y4 Bfd_Disabled
     *   Should an Error be placed in the log if Bfd_Disabled occurs and BfDstrictEnable is true?
  *   Event TBD-Y5 BfdHoldTimer_Expires
     *   What happens if BfdEnabled is False?
     *   What happens if BfdStrictEnable is FALSE?

  1.  8.1 - paragraph 4, beginning "If BFD strict-mode"



    Old text:/   I.e., no unexpected timers are running, and the BGP session's

   transition to Established is not lingering on a pending event./



     "i.e." means - That is. If you trying to indicate



     New text:/

      If Timers (list of timers) are not running, the BGP session transition to Established.

      If timers (list of timers) are running, ____ happens."



4.  Section 8.3

Section 8.3 (8.3.1, 8.3.2, 8.3.3, 8.3.4) should consider my questions on the events.



5.  Section 8.4

Section 8.4 (8.4.1, 8.4.2, 8.4.4, 8.4.5) should consider my questions on the events.



6.  Section 8.5

Section 8.5 (8.5.1, 8.5.2, 8.5.3) consider whether it check for BfdStrictEnabled is set.



7.  Section 8.6

Section 8.6.1 - should consider if the BfdEnable and BfdStrictEnable are set?

Section 8.6.3 - should consider if BfdEnable is set.



8.  Section 8.7

Section 8.7.1 - should consider if the BfdEnable and BfdStrictEnable are set?

Section 8.7.3 - should consider if BfdEnable is set as well as BfDStrictEnabled





9.  Section 10 - Unclear sentence



Current text:

   To avoid deadlock when utilizing both BFD hold-down and BFD strict-

   mode, when strict-mode is enabled for a peer, the BGP FSM MUST be

   enabled.  That is, BFD hold-down procedures MUST NOT prevent BGP from

   establishing a connection with the remote BGP speaker./



   How can the BGP FSM not be enabled?  Perhaps this is just editorial.





10.Interactions with draft-ietf-idr-bgp-fsm-iana-00



        If you are creating substates, Should create a substate registry?




Editorial issue


  1.  Section 8.1 paragraph 4, beginning "If BFD strict-mode"

Editorial:  grammar error

        Old text:/ If BFD strict-mode configuration is changed once the BGP FSM has
   started executing, but has not reached the Established state, the
   session is reset to the Idle state to ensure consistent behavior./

        New text:/ If BFD strict-mode configuration is changed once the BGP FSM has
   started executing but has not reached the Established state, the
   session is reset to the Idle state to ensure consistent behavior./

     I am assuming the if clause is:
   / If BFD strict-mode configuration is changed once the BGP FSM has
   started executing but has not reached the Established state,/

  Then clause is:
   Then - the BGP session is reset to the Idle state to ensure consistent behavior./


  How do you mean the BGP FSM has started executing?  Are you meaning non-Idle state or something else?


I hope this is helpful.

Cheerily, Sue