Hi Tim, 

Thanks again for the detailed review and digging into the IPv6 operations. 

> On Mar 3, 2023, at 4:34 AM, Tim Chown <[email protected]> wrote:
> 
> Hi Acee,
> 
>> On 2 Mar 2023, at 16:45, Acee Lindem <[email protected]> wrote:
>> 
>> [You don't often get email from [email protected]. Learn why this is 
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>> 
>> Hi Tim,
>> 
>> Thanks for your detailed review. I have some questions and comments on your 
>> comments. The rest of your comments were clear.
>> 
>>> On Mar 2, 2023, at 9:03 AM, Tim Chown via Datatracker <[email protected]> 
>>> wrote:
>>> 
>>> Reviewer: Tim Chown
>>> Review result: Has Nits
>>> 
>>> Hi,
>>> 
>>> This draft is not yet submitted to the IESG. Comments and reviews were
>>> solicited before taking the document further.
>>> 
>>> This draft is an update to RFC 5798, VRRP v3 for IPv4 and IPv6. It changes
>>> terminology to be more inclusive, applies errata, makes a small number of
>>> technical changes, and extends the security considerations.
>>> 
>>> Overall, the draft seems to be progressing well as an update, and I would
>>> encourage the authors to continue that process, while also taking on board 
>>> the
>>> comments below, some of which are general or open but others more specific. 
>>>  I
>>> would say it’s Ready with Nits.
>>> 
>>> The document remains well-written, with an easy to read style.
>>> 
>>> Comments:
>>> 
>>> Abstract and first para of Introduction:
>>> The second sentence should reflect that 5798 is now in the past.  It can
>>> mention 3768 but that’s now a previous version.
>> 
>> The fact that this document obsoletes RFC 5798 is in the abstract and intro. 
>> RFC 3798 still is the definitive reference for VRRPv2. I don’t think any 
>> update is needed here.
> 
> It just reads a bit awkwardly for me, where the revision from 5798 isn’t 
> mentioned in the first two sentences, but it says "It is version three (3) of 
> the protocol” and then at the end it says " This document obsoletes VRRP 
> Version 3 [RFC5798].” What’s obsolete is RFC5798, not VRRPv3.
> 
> It might be clearer to delete that last sentence and change the first two 
> sentences
> 
> "This document defines the Virtual Router Redundancy Protocol (VRRP) for IPv4 
> and IPv6.  It is version three (3) of the protocol, and it is based on VRRP 
> (version 2) for IPv4 that is defined in RFC 3768 and in "Virtual Router 
> Redundancy Protocol for IPv6”.
> 
> to
> 
> “This document defines version 3 of the Virtual Router Redundancy Protocol 
> (VRRP) for IPv4 and IPv6. It is based on VRRP (version 2) for IPv4 that is 
> defined in RFC 3768 and in "Virtual Router Redundancy Protocol for IPv6”, and 
> obsoletes the prevision specification of this version documented in RFC 5798.

This is a good suggestion and one that would improved the abstracts of other 
BIS documents. I will incorporate. 



> 
>>> Section 1.4:
>>> 
>>> “Hosts will learn the default routers in a few minutes” - in practice it is
>>> faster as hosts will send an RS when their interface comes up?
>>> 
>>> Is it really 38 seconds to determine a router is unreachable?  RFC 7048
>>> suggests it’s 3 seconds, and that that is (by the title) too impatient?
>>> 
>>> Are router preferences relevant here as per RFC 4191?
>> 
>> I really don’t want to get into a precise IPv6 ND specification in this 
>> document. How about if I update both of these to say “can take 10s of 
>> seconds”?
> 
> That’s fine. I don’t have enough experience to know what the figure is.  
> Saying 38 seconds seems very precise unless there’s a specific reason for the 
> figure, and it is much more than the 3 seconds indicated in RFC 7048.  Saying 
> “can take a few tens of seconds” seems fine, if that’s operational experience.

I believe this originally came from the original VRRP IPv6 draft that was 
incorporated into VRRPv3. I’m sure the numbers have changed over time.  


> 
>>> 
>>> Section 1.7:
>>> 
>>> Maybe add VR ID to the definitions
>>> 
>>> Section 4.2:
>>> 
>>> Should H3 and H4 here have IPvX B rather than A?
>>> 
>>> Section 7.4:
>>> 
>>> I think 2464 should be replaced by RFC 7217?  If so, maybe mention that the 
>>> Net
>>> Interface element of the algorithm should maybe be the virtual MAC not the
>>> physical one?
>> 
>> I don’t think I have to replace RFC 2464 since RFC 7217 doesn’t even update 
>> it. I could add it but I think we want to use the physical MAC consistent 
>> with the RFC 2464 recommendation.
> 
> I’m quite surprised that section 4 of RFC 2464 hasn’t been obsoleted in some 
> way.
> 
> I’d point you at bullet 5 of section 4 of RFC 7217, and I’d be surprised if 
> you didn’t draw IESG comments about this when the document reaches that 
> stage.  I think your aim with this review is to catch things before that 
> stage, hence I’m flagging it.  For some it is likely to be a DISCUSS level 
> comment.
> 
> Whether physical or virtual MAC is an interesting question.

I’ll get back to you on this one. I just scanned RFC 7217 the first time. 



> 
>>> 
>>> Section 11:
>>> 
>>> Should the protocol number registry be added here, where VRRP is 112 and 
>>> cited
>>> as RFC 5798?
>> 
>> I agree but the IANA registry should be updated to this document since it 
>> obsoletes RFC 5798.
> 
> OK, I’m not 100% sure what needs to be captured in the IANA considerations, I 
> mentioned it as it will need updating, and I’d assumed IANA would check the 
> IANA sections of new RFCs as part of their process.  But happy to defer to 
> your experience.

I’ve added it. 

> 
>>> Finally, I did stumble across some comments in section 7 of RFC 6527 while
>>> reading around the topic, on ambiguities for multi-stack VRRP operation. 
>>> Should
>>> this draft bring those into scope, or leave them out?  If the latter, 
>>> perhaps
>>> state this in the document.
>> 
>> 
>> I believe RFC 6527 is wrong. IPv4 and IPv6 virtual routers are always 
>> treated as separate logical instances. Note that the abstract says:
>> 
>>    "Within a VRRP router, the virtual routers in each of the IPv4 and IPv6 
>> address families are independent of one another.”
>> 
>> Note that “routers” is plural. I’d disagree with any other interpretation.
> 
> OK, that’s fine.  Maybe just add that sentence then, in section 1.2?  "IPv4 
> and IPv6 virtual routers are always treated as separate logical instances.”  
> It may be obvious and unambiguous to you, but stating it can do no harm?

Sure. We should obsolete RFC 6527 as well - Aditya is taking the lead on that 
one as Cisco has implemented the MIB. I’m going to update the VRRP YANG model 
next. 

Thanks,
Acee


> 
> Best wishes,
> Tim
> 
>> 
>> Thanks,
>> Acee
>> 
>> 
>>> 
>>> Tim
>>> 
>>> 
>> 
> 

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