Hi, Greg, The bfd.SessionType is really a core state variable to the original BFD spec — just implicitly defined. This is made explicit by the “PointToPoint” value from draft-ietf-bfd-multipoint-11, but that does not mean that RFC 7880 and RFC 5880 need to be revised to add this.
Using SBFDNone (or something like it) is harmful, because that covers a set of multiple values (PointToPoint and MultipoitntHead are both SBFDNone). Net-net, I still do not believe, on technical grounds, that there’s any change needed to RFC 7880 or RFC 5880. The one change to consider is to have draft-ietf-bfd-multipoint-11 update RFC 5880 by saying that no value means PointToPoint. Thanks, — Carlos Pignataro, [email protected]<mailto:[email protected]> “Sometimes I use big words that I do not fully understand, to make myself sound more photosynthesis." On Dec 19, 2017, at 11:29 PM, Greg Mirsky <[email protected]<mailto:[email protected]>> wrote: Hi Carlos, et.al<http://et.al/>, I agree that for a BFD node that in addition to RFC 7880 supports draft-ietf-bfd-multipoint bfd.SessionType will not be left unset when the BFD session is other than of S-BFD type (PointToPoint, MultipointHead or Multipoint Tail). But if the BFD node only supports base BFD [RFC5880] and S-BFD [RFC7880] specifications bfd.SessionType is unspecified if the session type is neither SBFDInitiator, nor SBFDReflector. Making resolution of this issue to be dependent on support of BFD for Multipoint Networks doesn't seem as prudent approach. I'm open to suggestions of the better name for the new value of bfd.SessionType, other than SBFDNone. Regards, Greg On Mon, Dec 18, 2017 at 6:28 PM, Carlos Pignataro (cpignata) <[email protected]<mailto:[email protected]>> wrote: As a co-author of RFC 7880, I disagree with the report below, and recommend Rejecting this Erratum. S-BFD uses the BFD state variables, and “bfd.SessionType” is applicable with finer granularity than “Not S-BFD”. Some details at. https://mailarchive.ietf.org/arch/msg/rtg-bfd/HxHT6Nxhpxot4baDag7cW6gm_ZQ Further: The proposed value of “SBFDNone” is covered at https://tools.ietf.org/html/draft-ietf-bfd-multipoint-11#section-4.4.1 with the values of either “PointToPoint” (classing, p2p, BFD), “MultipointHead”, and “MultipointTail” (plus “MultipointClient”) Including a new state variable and new values for the bfd.SessionType adds unnecessary complexity. — Carlos Pignataro, [email protected]<mailto:[email protected]> “Sometimes I use big words that I do not fully understand, to make myself sound more photosynthesis." On Dec 16, 2017, at 3:27 PM, RFC Errata System <[email protected]<mailto:[email protected]>> wrote: The following errata report has been submitted for RFC7880, "Seamless Bidirectional Forwarding Detection (S-BFD)". -------------------------------------- You may review the report below and at: http://www.rfc-editor.org/errata/eid5211 -------------------------------------- Type: Technical Reported by: Greg Mirsky <[email protected]<mailto:[email protected]>> Section: 6.1 Original Text ------------- o bfd.SessionType: This is a new state variable that describes the type of a particular session. Allowable values for S-BFD sessions are: * SBFDInitiator - an S-BFD session on a network node that performs a continuity test to a target entity by sending S-BFD packets. * SBFDReflector - an S-BFD session on a network node that listens for incoming S-BFD Control packets to local entities and generates response S-BFD Control packets. The bfd.SessionType variable MUST be initialized to the appropriate type when an S-BFD session is created. Corrected Text -------------- o bfd.SessionType: This is a new state variable that describes the type of a particular session. Allowable values for S-BFD sessions are: * SBFDNone - indicates that the BFD session is not of S-BFD type. * SBFDInitiator - an S-BFD session on a network node that performs a continuity test to a target entity by sending S-BFD packets. * SBFDReflector - an S-BFD session on a network node that listens for incoming S-BFD Control packets to local entities and generates response S-BFD Control packets. The bfd.SessionType variable MUST be set to SBFDNone when a BFD session other than S-BFD. The bfd.SessionType variable MUST be initialized to the appropriate type when an S-BFD session is created. Notes ----- The original text leaves value of the new variable bfd.SessionType unspecified if the type of BFD session is other than S-BFD. Instructions: ------------- This erratum is currently posted as "Reported". If necessary, please use "Reply All" to discuss whether it should be verified or rejected. When a decision is reached, the verifying party can log in to change the status and edit the report, if necessary. -------------------------------------- RFC7880 (draft-ietf-bfd-seamless-base-11) -------------------------------------- Title : Seamless Bidirectional Forwarding Detection (S-BFD) Publication Date : July 2016 Author(s) : C. Pignataro, D. Ward, N. Akiya, M. Bhatia, S. Pallagatti Category : PROPOSED STANDARD Source : Bidirectional Forwarding Detection Area : Routing Stream : IETF Verifying Party : IESG
