[Gen-art] Gen-art review: draft-ietf-6renum-gap-analysis-05.txt

[Robert Sparks <[e-mail]>]

I am the assigned Gen-ART reviewer for this draft. For background on
Gen-ART, please see the FAQ at

<http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.

Please resolve these comments along with any other Last Call comments
you may receive.

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.