Hi Dan, Could you look at the recently posted version -05 to see if this resolves your comments? Thanks, Donald =============================== Donald E. Eastlake 3rd +1-508-333-2270 (cell) 155 Beaver Street, Milford, MA 01757 USA d3e3e3@xxxxxxxxx On Wed, Jan 18, 2017 at 2:16 PM, Donald Eastlake <d3e3e3@xxxxxxxxx> wrote: > Hi Dan, > > On Tue, Jan 17, 2017 at 3:45 AM, Dan Romascanu <dromasca@xxxxxxxxx> wrote: >> Hi Donald, >> >> Thank you for your answer and explanations. They make sense to me, but I >> still beleive that the document may benefit if some edits are being done to >> clarify what may be the obvious for the people who know all details and >> history, but not for the other users of the document in the future - >> implementers and operators. > > Sure, I agree that it would benefit for the addition of some text here > and there./ > >> Specifically: >> >>> I am not aware of any case where this draft replaces a TLV in the >> sense of requiring use of a new TLV. It does provide some new TLVs >> and procedures that are believed to be superior to or useful additions >> to previous ones. But I am not aware of any case where it "obsoletes" >> previous provisions in the sense of prohibiting their use. >> >> The header of the document includes Obsoletes 6439. If part of the content >> of 6439 remains valid this needs to be clarified, If some superior TLVs and >> procedures are introduced there is a need to explain what will happen with >> the previous ones. Should they be implemented? deployed? activated? > > OK. Stating that essentially all of RFC 6439 is incorporated and > outlining what parts of the new draft are optional improvements over > which part of RFC 6439, etc. would probably be a good addition. > >>> I don't know that much is really required to be said about >> "transition" when you specify an optional optimization. Since it is >> optional, by implication the implementer is free to use it or not and >> things will work either way. This could be stated explicitly in those >> cases. >> >> If I understand what you say, the new features are optional (although the >> status of the document is Proposed Standard), they can or cannot be >> implemented (one, the other, both?) and the network will still work. Yes, I >> suggest to explicitly state this). > > OK. > >>> RFC 6325, the base TRILL protocol RFC, says TRILL switches (RBridges) >> SHOULD support SNMPv3 and there are TRILL MIB specifications in RFCs >> 6850 and 7784. However, there are also YANG modules underway in >> draft-ietf-trill-yang, draft-ietf-trill-yang-oam, and >> draft-ietf-trill-yang-pm. >> >>> It does not seem best for this rfc6439bis draft to change the >> implementation requirement level for SNMP or NETCONF for TRILL. If that >> were to be done, it seems like something more appropriate for the base >> TRILL YANG draft (draft-ietf-trill-yang-*) to do. >> >> If I was an implementer of TRILL, or an operator considering to deploy >> TRILL, I would have a hard time trying to understand what to implement and >> what to deploy as management interfaces. Maybe this is not the place but I >> believe that there need to be some documentation on this respect. > > OK. I think it would be reasonable to say something about the current > implementation requirement level of SNMPv3 and to say that YANG > modules are under development, so implementers will know more about > what is going on. > > Thanks, > Donald > =============================== > Donald E. Eastlake 3rd +1-508-333-2270 (cell) > 155 Beaver Street, Milford, MA 01757 USA > d3e3e3@xxxxxxxxx > >> Thanks and Regards, >> Dan >> >> >> On Tue, Jan 17, 2017 at 3:48 AM, Donald Eastlake <d3e3e3@xxxxxxxxx> wrote: >>> >>> Hi Dan, >>> >>> Thanks for your review. As per my further response below, while the >>> draft could perhaps use some clarifying additions related to >>> operations, I do not believe it is as bad as you say. >>> >>> On Thu, Jan 12, 2017 at 11:04 AM, Dan Romascanu <dromasca@xxxxxxxxx> >>> wrote: >>> > >>> > Reviewer: Dan Romascanu >>> > Review result: Has Issues >>> > >>> > I have reviewed this document as part of the Operational >>> > directorate's ongoing effort to review all IETF documents being >>> > processed by the IESG. These comments were written with the intent >>> > of improving the operational aspects of the IETF drafts. Comments >>> > that are not addressed in last call may be included in AD reviews >>> > during the IESG review. Document editors and WG chairs should treat >>> > these comments just like any other last call comments. >>> > >>> > This document clarifies and updates the TRILL Appointed >>> > Forwarder mechanism. It updates RFC 6325, updates RFC 7177, and >>> > obsoletes RFC 6439. >>> > >>> > It's a complex document which requires extra reading to understand >>> > the context and the interraction with other RFCs. I believe that >>> > from an OPS-DIR perspective there are issues that need to be >>> > discussed before the document can be approved. >>> > >>> > The main issues with the document in its current form are: >>> > >>> > 1. The document makes consistent changes in the way TRILL >>> > operates. It replaces TLVs and procedures, define new ones, >>> > obsoletes previous mechanisms that define VLAN mapping, and >>> >>> I am not aware of any case where this draft replaces a TLV in the >>> sense of requiring use of a new TLV. It does provide some new TLVs >>> and procedures that are believed to be superior to or useful additions >>> to previous ones. But I am not aware of any case where it "obsoletes" >>> previous provisions in the sense of prohibiting their use. >>> >>> > incorporates updated material from other RFCs. There is however no >>> > indication in the text about the transition between existing >>> > deployed versions of TRILL based on RFC 6439 and related protocols >>> > with the current updated mechanisms. Are these backward compatible? >>> >>> I don't know that much is really required to be said about >>> "transition" when you specify an optional optimization. Since it is >>> optional, by implication the implementer is free to use it or not and >>> things will work either way. This could be stated explicitly in those >>> cases. >>> >>> Much of the material in this draft comes from RFC 6439 or the parts of >>> RFC 7177 that updated RFC 6439. Most of the new material is optional >>> improved behaviors. >>> >>> The only mandatory new behavior is the mandatory support of the link >>> local E-L1CS flooding scope [RFC7357] specified in Section 8. There is >>> material in this draft covering backwards compatibility for this new >>> mandatory behavior. Section 8 already explains how to determine >>> whether or not all TRILL switches on a link support E-L1CS flooding >>> scope. The only use of E-L1CS flooding scope in this draft is as part >>> of a mechanism for the DRB (Designated RBridge (TRILL switch)) to >>> advertise Forwarder Appointments and, as stated in Section 2.1 (see >>> paragraph at the bottom of page 8 in draft -04), if any RBridge on the >>> link does not support E-L1CS, then the DRB MUST fall back to >>> advertising those appointments in Hellos. Section 8, which mandates >>> support of E-L1CS, also requires that any use of E-L1CS specified in >>> the future must provide for backward compatibility. >>> >>> > Do they need a simultaneous upgrade of the whole network? >>> >>> No. >>> >>> > 2. The document lacks a section or even minimal text concerning >>> > operational and manageability considerations. There are several >>> >>> Such a section can be added but there is not much to say. For example, >>> as explained below, there is very little specified in this document to >>> configure. >>> >>> > mentions in the text concerning network managers or operator >>> > actions, but there is no indication or reference to what management >>> > protocols and data models are to be used for configuration, >>> >>> RFC 6325, the base TRILL protocol RFC, says TRILL switches (RBridges) >>> SHOULD support SNMPv3 and there are TRILL MIB specifications in RFCs >>> 6850 and 7784. However, there are also YANG modules underway in >>> draft-ietf-trill-yang, draft-ietf-trill-yang-oam, and >>> draft-ietf-trill-yang-pm. >>> >>> It does not seem best for this rfc6439bis draft to change the >>> implementation requirement level for SNMP or NETCONF for TRILL. If that >>> were to be done, it seems like something more appropriate for the base >>> TRILL YANG draft (draft-ietf-trill-yang-*) to do. >>> >>> > retrieval of operational status information, or alerts. I believe >>> > that these need to be added explicitly or by reference. >>> >>> Reviewing the significant protocol additions in this draft at a high >>> level: >>> >>> - There is significant material about the various ways the Designated >>> RBridge on a link can announce who it is selecting as the Appointed >>> Forwarder on the link for various VLANs. The election of the >>> Designated RBridge depends on a configurable priority but that >>> election is unchanged from RFC 7177 and in fact is identical to the >>> election of the designated router on any IS-IS link. The decision on >>> which RBridges to appointer as forwarder for which VLAN is out of >>> scope. I don't see that there is anything to configure here, other >>> than RBridge priority to be DRB, which is already specified in other >>> RFCs. >>> >>> - There are some optional optimizations to the inhibition mechanism. >>> The inhibition mechanism is necessary for loop safety but any >>> RBridge can use or not use any of these optimizations, as they >>> choose, and things will work fine. >>> >>> - Port Shutdown message: There are two new configuration parameters >>> here, namely how many copies of the Port Shutdown message to send >>> and at what interval. These are listed, along with units and default >>> value in Section 6.6. >>> >>> - FGL-VLAN mapping consistency check: As specified in RFC 7172, in a >>> TRILL campus supporting Fine Grained Labels (FGL), the VLAN of a >>> native frame can be mapped to an FGL on ingress and an FGL is mapped >>> to a VLAN on egress. This draft makes no changes to that mechanism. >>> It merely provides that an RBridge performing such mapping can >>> optionally advertise the mapping it is performing at a port to other >>> RBridges with ports on the same link which can then check it for >>> consistency with any mapping they are performing. It is recommended >>> that the network operator be alerted to such inconsistency and there >>> is a configurable parameter for how long the inconsistency needs to >>> exist before such alert. Is it your position that some specific >>> protocol mechanism must be specified by which the network operator >>> is alerted? >>> >>> Thanks, >>> Donald >>> =============================== >>> Donald E. Eastlake 3rd +1-508-333-2270 (cell) >>> 155 Beaver Street, Milford, MA 01757 USA >>> d3e3e3@xxxxxxxxx >> >>