Subject: [ftpext] I-D Action: draft-ietf-ftpext2-ftp64-01.txt

From: [email-masked]
Date: Sun, 10 Jul 2011 19:18:24 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the FTP Extensions, 2nd edition Working Group of the IETF.

	Title           : FTP extension for IPv4/IPv6 transition
	Author(s)       : Dapeng Liu
                          Iljitsch van Beijnum
                          Zhen Cao
	Filename        : draft-ietf-ftpext2-ftp64-01.txt
	Pages           : 7
	Date            : 2011-07-10

   The File transfer protocol, which is defined by the RFC 959, has a
   long history, but still being widely used.  The original version of
   FTP specification defines IPv4 version of FTP.  RFC 2428 defines IPv6
   extensions of FTP, introducingEPRT and EPSV command.  In the IPv6-
   IPv4 translation scenario, considerations should be applied to FTP
   client, server and translation box to ensure FTP protocol work
   properly.  This document discusses the details for FTP to work in
   IPv4-IPv6 transitiion scenario.  This document proposes to update
   IPv6 FTP client&#39;s specification to make it easier to work in 6to4
   scenario.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-ftpext2-ftp64-01.txt

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

This Internet-Draft can be retrieved at:
ftp://ftp.ietf.org/internet-drafts/draft-ietf-ftpext2-ftp64-01.txt

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From: John C Klensin <[email-masked]>
Date: Sun, 10 Jul 2011 22:58:18 -0400

>    The File transfer protocol, which is defined by the RFC
> 959, has a long history, but still being widely used.  The
> original version of FTP specification defines IPv4 version
> of FTP.

This is obviously not a big deal --I'll have more real comments
on the draft later-- but the above statement from the abstract
is unquestionably false.

The original version of the FTP specification was published in
April 1971 in RFC 114, long before IPv4 was even imagined.  It
defined the NCP version of FTP for the ARPANET.

  -- john
    (Aka cranky old guy who was somewhat involved in the
original design and who has been using FTP since 1971)

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From: Mykyta Yevstifeyev <[email-masked]>
Date: Mon, 11 Jul 2011 06:49:06 +0300

> on the draft later-- but the above statement from the abstract
+1
> defined the NCP version of FTP for the ARPANET.
Actually this is true.  The first document which specified FTP as we 
currently know it was RFC 354, though.  But the concept was set in RFC 114.

Mykyta
> _______________________________________________
> ftpext mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/ftpext
>

---

From: Mykyta Yevstifeyev <[email-masked]>
Date: Mon, 11 Jul 2011 12:09:47 +0300

Hello,

I'd like to provide some comments on this draft.  (Sorry John if I 
hijack some of what you wanted to say.)

>     RFC 2428 defines IPv6
>     extensions of FTP, introducing EPRT and EPSV command.

The EPRT and EPSV commands are really scoped mainly to IPv6 addresses, 
but not only.  It uses the RIP address family identifier 
(http://www.iana.org/assignments/address-family-numbers/address-family-numbers.xml) 
to allow addresses in the format other that used with IPv4.  So I think 
the aforementioned statement should be corrected.  The same applies to 
Introduction.

Section 1:

>     It should be noted that in some scenario, the FTP client that running
>     on the IPv6 host maybe legacy IPv4 FTP client.

There is no explicit explanation of what does the "legacy IPv4 FTP 
client" mean.  Moreover, no explicit statement on what should be 
considered to be "IPv4/IPv6 client/server" is provided as well.

Section 5:

>     This document argues that since FTP is a protocol that could avoid
>     ALG by slightly adjusting the operation of the IPv6 FTP client it is
>     not recommended the translation box to implement FTP ALG.

Your document does not explain what does the "ALG" mean.

Section 6:

>     The extension that
>     defines in this document will not impact FTP security.

First, s/defines/is defined/ (this is not an only instance of such 
mistakes in the document).  Second, I don't see the "extension" in your 
document.  (This also applies to title).

The intended status is Informational.  However, I'd better like BCP, 
since your document tries to make normative recommendation.  Moreover, 
in Abstract you say:

>     This document proposes to update
>     IPv6 FTP client's specification

What document is the "IPv6 FTP client's specification"?

Also, some conclusion summarizing the document's recommendation will be 
useful.

Thanks,
Mykyta Yevstifeyev