Last Call Review of draft-ietf-6renum-gap-analysis-05
review-ietf-6renum-gap-analysis-05-genart-lc-sparks-2013-04-01-00

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Document: draft-ietf-6renum-gap-analysis-05.txt
Reviewer: Robert Sparks
Review Date: April 1, 2013
IETF LC End Date: April 10,2013
IESG Telechat date: Not yet scheduled for a telechat

Summary: This document is not ready for publication as an Informational RFC.
         It may be on the right track, but there issues both in substance
         and form that need to be addressed.

Major issues:



The document doesn't provide what its title and abstract claim it will 


provide.


For instance, the abstract claims a gap analysis is presented following 


a renumbering


event procedure summary, but neither appear in the draft. There are a 


few places


in the text that say "this is a gap", but usually it's not clear what 


"this" means.




The stated intent is to identify missing capabilities (gaps) and the work


needed to provide them. The document should lay these out very clearly. 


As the



document is currently written, it is difficult to pull out a simple list of
identified gaps. While addressing that, it would help more to provide some
sense of the relative importance of addressing each of the gaps identified.

There are several significant issues with clarity. I will point to the most
difficult in a section below.

----------------------
Minor issues:



The document currently references draft-chown-v6ops-renumber-thinkabout 


several times.


That document is long expired (2006). It would be better to simply 


restate what is


important from that document here and reference it only once in the 


acknowlegements



rather than send the reader off to read it.



RFC4076 seems to say very similar things to this document. Should it 


have been referenced?






Section 5.3 punts discussion of static addresses off to RFC 6866. That 


document was scoped


only to Enterprise Networks. The scope of this document is larger. Are 


there gaps because


of that difference in scope that were missed? Would it make sense to 


summarize any gaps



RFC 6866 identified that are relevant to this document here?



Should section 8 belong to some other document? It looks like 


operational renumbering


advice/considerations, but doesn't seem to be exploring renumbering 


gaps, except for


the very short section 8.2 which says "we need a better mechanism" 


without much explanation.





----------------------
Text needing clarity (more than nits):



Section 4.1, second paragraph: The first sentence needs to be 


simplified. Something like


"Delegation routers may need to renumber themselves with new delegated 


prefixes" perhaps.


The second sentence speaks of "the router renumbering issue" as if it's 


clear which particular


issue you're actually talking about. Is there a gap here? If so, 


consider replacing the entire



paragraph with an explicit description of the gap.



Section 5.1, first bullet, 2nd paragraph: The third sentence (starting 


"In ND protocol,")



makes no sense. The fourth sentence is also hard to parse.



Section 5.1, first bullet. The list below "the impact of ambiguous M/O 


flags" says things like


"there is no standard" and "it is unspecified". I think you are trying 


to say that there is


ambiguity in what's written, not that nothing's written. This entire 


list would benefit from



being recast in terms of what needs to be done (what are the gaps?).



Section 5.2, last paragraph. It's not clear what you are trying to say 


here. Is it simply


that the natural pressures in an ISP make it more likely that an ISP 


would choose to use


DNS names as part of configuration than an enterprise would? If so, can 


you list what some



of those pressures are? What gap is this discussion trying to identify?



Section 6.1, first paragraph, first sentence (starting "For DNS records 


update") - this sentence


does not parse. What is it trying to say, and what's the gap you are 


trying to point to?






Section 6.3, 6th paragraph. "So there's a big gap for configuration 


aggregation" is


unclear. Is it that configuration isn't stored in one place, or that it 


can't be



found through one place, or something different?



Section 7.1 second bullet. Taking this partial quote from RFC4192 


destroyed the meaning


of the sentence. The original sentence said "The suggestion applies" - 


this misquote says


"reducing the delay applies". There's no benefit to quoting 4192 


directly - say what you



mean and reference 4192.


----------------------
Nits/editorial comments:



There are a few sentences ending with "etc." in the document. Please 


consider deleting the



word from the list - it doesn't help each sentence make its point.



Introduction: "Future efforts may be achieved in the future." doesn't 


add anything



to the document. I suggest deleting the sentence.

Section 3.2: Consider deleting "basically" from "an IPAM is basically used"



Section 5.1: draft-ietf-dhc-host-gen-id is no longer new (and it 


definitely will not be


new a few years after this is published as an RFC. Please remove "the 


new IETF DHC WG



document" from the sentence it appears in.



Section 5.1: This sentence "Using these flags, the two separated address 


configuration


modes are somehow correlated." is not clear. ("somehow" isn't going to 


help the reader


in any case). Are you trying to say "This flags provide some degree of 


correlation in


the use of these separate configuration protocols"? Could you rewrite 


this explicitly



identifying gaps?

Section 5.1: Please delete "mainly" from "flags mainly includes"



Section 5.2 (and other places): Is it really the case that router 


operators have to


resort to restarting routers in order to pick up configuration changes 


these days?


RFC2072 pointed to that, and in 1997 it may have been more routine to 


restart, but


for modern systems, that action is more extreme. Surely for something as 


basic as



a cache-clear, restarts are vanishingly rare.



Section 5.3: Instead of "the static address issue" could you say 


"discussing the



problems associated with renumbering hosts with static addresses"?



Section 6, first paragraph: It's not clear what "the entries in the 


site" means.


What's a site and what are entries in this case.  I suggest "then any 


configuration


or data store containing the previous number must be updated." as a 


replacement, and


then say "Some examples include:" and list DNS records and ACLs. 


Consider pointing


forward to the section on DNS Authority listed under "Gaps considered 


unsolvable".


Note that some of those ACLS are going to be on machines under control 


by another



authority, having the same problem you point to for DNS.



Section 6.1: What do you mean by "the major DNS systems". Do you mean 


the major



implementations like BIND?

Section 6.2, first paragraph. This suffers from the ambiguity of the word
"records". You meant it as a verb (DNS writes something down) instead of
a noun (the DNS system contains DNS records). I suggest rewriting this
paragraph to avoid the ambiguity. "While DNS entries contain addresses" -
"Hosts are configured with" - "hosts must update these addreses"

Section 6.2 second paragraph. Please be more clear what you mean by
"DNS lifetimes". You are not trying to refer to the time-to-live of
a DNS record. Rather, you are trying to say how long a bit of configuration
obtained through DHCP should be considered relevant. If there's a gap
(a need for more protocol), please be explicit. You will proabably want
to engage the DHC working group if you are thinking about asking that
DHCP tell you how long DNS server configuration value is good for if you
are really trying to decouple it from the lease time. (Is that what
you're suggesting? If not, then what's the problem?)

Section 6.3, second bullet, second sub-bullet: What does "the entries" mean?


Please be specific. Do you mean "configured addresses or prefixes" or 


something



else? Or is this intended to extend to updating things like DNS zone files?
As written, it is vague.

Section 6.3, last sentence. "It is a big gap currently." What specifically


is the big gap. Is it a lack of a standard protocol for updating 


configurations



so that there won't be some many vendor-private protocols deployed?
Please consider replacing "It" with something explicit.



Seciton 7.1: The first bullet does not parse. If I guess its meaning 


correctly


(that it would be benificial to tell hosts that local DNS has been 


updated and


they may want to make fresh queries), please be careful with the 


wording. The



hosts don't know which names are likely to resolve locally.



Section 7.1, third bullet - This isn't obviously about notification. Why 


is it



in this section? What's the gap this is trying to identify?

Section 7.2 - how is this section helping the document? What are the gaps?



Section 7.3 - again, how is this section helping the document acheive 


its goal?


Would anyone working to close gaps do anything differently if this 


section were



deleted?



Section 9.4 - what is it about these that make them gaps, much less 


unsolvable gaps.



Is this discussion in the wrong section of the document?

Section 10 - The sentence starting "In the LAN" doesn't parse. Did you mean
"may be needed to"?



Section 10, last paragraph: This sentence doesn't make sense. It would 


make more


sense if you replaced "blocking access" with "protecting", but it would 


be even



better to expand the discussion and explain what you mean by interruption.