Subject: Re: ipv6-smtp-requirement comments?
From: Eric Allman <[email-masked]>
To: Bob Fink <[email-masked]>
Cc: [email-masked], [email-masked], NGtrans List <[email-masked]>
Date: Mon, 29 Oct 2001 16:27:14 -0800
List-Id: <ietf-smtp.imc.org>

I think there is some ambiguity in section 3.  In particular, the
numbering seems to combine looping and gotos in a confusing way.
For example, consider the case of doing an A (or AAAA) lookup that
returns multiple IP addresses.  Step (6) says to loop from (7) to
(8) on each address returned, but step (8) says to to back to step
(3).  Which one is it?  This is doubly confusing because step (8)
can never be executed more than once in the innermost loop [(7)-(8)],
so really you are looping on step (7) only -- assuming that the goto
(3) takes precedence over the loop (7)-(8).

Now, _I_ know what they are trying to say, but the language could
be cleaned up -- making this either a loop model or a goto model
should fix it.

Also in section 3, step (5) doesn't say what to do if the resulting
list is empty.  The example at the top of the section lists a host
mx10.example.org that is IPv6 only.  If the source MTA is IPv4 only,
then the lookup of mx10.example.org is going to fail with NO_DATA.
Step (5) should address this.

eric

To: [email-masked]
Cc: [email-masked], [email-masked], NGtrans List <[email-masked]>
Subject: Re: (ngtrans) Re: ipv6-smtp-requirement comments? 
From: [email-masked]
Date: Mon, 29 Oct 2001 09:49:20 +0900
Sender: [email-masked]

>In section 5, there is a discussion of SERVFAIL returns from broken DNS
>servers (which I've seen myself in production).  That could use a one-sentence
>clarification that the problem is the DNS server only having A records for
>an address, and returning SERVFAIL rather than "no data" when asked for AAAA
>records.  
>
>We all know who the offender is, and those of us who use Sendmail already
>know why 'WorkAroundBrokenAAAA' exists.  I'll let somebody with more RFC-writing
>experience than I decide if package-specific "If you run the XYZ MTA, do THIS
>to work around it, if you run the ABC DNS server, upgrade to patch 1.15" info
>should be included in an "operational requirements" RFC.  RFC1912 mentions
>specific releases of BIND, RFC2010 doesn't.

	i don't think it necessary/required to list the broken implementation.
	i know of a couple of products that behave badly (which is an IP load
	balancing box product), but i don't think i can cover every broken
	implementations.

itojun

To: [email-masked], [email-masked], NGtrans List <[email-masked]>
Subject: Re: ipv6-smtp-requirement comments? 
From: [email-masked]
Date: Fri, 26 Oct 2001 08:54:29 -0400
Sender: [email-masked]

--==_Exmh_-1742651564P
Content-Type: text/plain; charset=us-ascii

On Thu, 25 Oct 2001 17:16:50 PDT, Bob Fink said:

> <http://www.ietf.org/internet-drafts/draft-ietf-ngtrans-ipv6-smtp-requirement-03.txt>
> 
> So, please let the ngtrans list now if you have any problems with 
> forwarding this draft, preferably by 1 November.

Technically, I see no major issues - there are a few places where I don't
think we *know* the "best current practice" yet, but those are all carefully
worded with "implementation dependent".

In section 5, there is a discussion of SERVFAIL returns from broken DNS
servers (which I've seen myself in production).  That could use a one-sentence
clarification that the problem is the DNS server only having A records for
an address, and returning SERVFAIL rather than "no data" when asked for AAAA
records.  

We all know who the offender is, and those of us who use Sendmail already
know why 'WorkAroundBrokenAAAA' exists.  I'll let somebody with more RFC-writing
experience than I decide if package-specific "If you run the XYZ MTA, do THIS
to work around it, if you run the ABC DNS server, upgrade to patch 1.15" info
should be included in an "operational requirements" RFC.  RFC1912 mentions
specific releases of BIND, RFC2010 doesn't.

Although Motonori's English is vastly superior to my Japanese,  I still saw
a few places where phrasing was awkward, or verbs had case/tense issues. I'd
consider them not a show-stopper, but if a volunteer from the audience were
to go through and clean them up, the document would benefit (I'll be happy
to do so if nobody else wants to, but consensus calls for a clean-up - but if
nobody else cares, I'll let it slide).

-- 
				Valdis Kletnieks
				Operating Systems Analyst
				Virginia Tech

--==_Exmh_-1742651564P
Content-Type: application/pgp-signature

--==_Exmh_-1742651564P--

Date: Thu, 25 Oct 2001 17:16:50 -0700
To: [email-masked], [email-masked]
From: Bob Fink <[email-masked]>
Subject: ipv6-smtp-requirement comments?
Cc: NGtrans List <[email-masked]>
Sender: [email-masked]

ietf-822 & ietf-smtp folk,

The following IETF NGTRANS ipv6-smtp-requirement I-D has just finished WG 
last call for forwarding as an Informational RFC. Randy Bush (our AD) 
suggested that we also circulate it to various groups that might have 
comments otherwise uncovered in ngtrans as it also covers practice.

<http://www.ietf.org/internet-drafts/draft-ietf-ngtrans-ipv6-smtp-requirement-03.txt>

So, please let the ngtrans list now if you have any problems with 
forwarding this draft, preferably by 1 November.

	NGtrans List <[email-masked]>

Thanks,

Bob Fink
ngtrans co-chair