Subject: Ftp-WG: Internet Explorer and anonftpd

From: "Jan Mikkelsen" <[email-masked]>
Date: Wed, 20 Oct 1999 18:03:31 -0400

D. J. Bernstein writes:
>The question of how well EPLF works with clients _now_ is a red herring.
>The transition plan does not ask servers to use EPLF _now_. It asks
>servers to switch at a time when switching _will_ work well.

The problem I see is one of logistics.  I'm sure others have seen it as
well.

My mother(!) uses Internet Explorer, but certainly not on a daily basis.
How do you get her (and others like her) to upgrade her machine?  I don't
think that question has been adequately answered, and this is the core of
the problem with your upgrade strategy.  How many "big bang" protocol
upgrades have been successful on the scale of today's Internet?  Or even one
tenth of the size of today's Internet?

Proxy servers will help greatly in this situation.  I have been visiting
your site for some time with IE4, and I haven't seen problems because Squid
handled everything correctly.  However, in a universal protocol upgrade many
people won't be using proxies.

Compared to the logistical and support effort involved in doing a "big bang"
upgrade, the development effort saved is miniscule.  Upgrading in multiple
stages is a net win, with lower risks.

[On FTP Clients and protocol conformance]

As a server implementor, I have experienced the bugginess of clients in
dealing with the output of LIST and their general disregard of standards.  I
agree with you that it is a bad thing, and they should all be fixed or hung
out to dry.  However, I don't want to try to fix them all at once.

Jan Mikkelsen

---

From: "D. J. Bernstein" <[email-masked]>
Date: Wed, 20 Oct 1999 19:10:51 -0400

Jan Mikkelsen writes:
> The problem I see is one of logistics.

I'm looking forward to seeing your strenuous objections to the HOST
command proposed here.

HOST-based virtual FTP service breaks all non-HOST clients. The only
safe way to make HOST work is _first_ to upgrade all the clients and
_then_ to upgrade the servers. There's no dispute about these facts.

You claim that your mother's machine will never be upgraded. You also
claim that this situation is typical. Your conclusion must therefore be
that the HOST transition plan is doomed to failure.

---Dan