Shortly after I installed Express3 which contains the FTPEDR3A FTP patch, our
weekly batch job that does an FTP download of payroll data from the FTP server
at our local county department of education bombed.

By running FTP.ARPA.SYS from a session and using the "debug" FTP command, I
discovered that this new FTP client will handle a download request of
"get foobar" by:

        RNFR foobar
        RNTO foobar
        PORT
        RETR foobar

The remote county non-MPE Bull FTP server chokes on the RNFR (rename from) as
unimplemented, and this return code confuses the MPE FTP client, which gives
up without completing the download.

The pre-Express3 FTP client did not do the RNFR/RNTO combination.  In talking
with both the HPRC and the lab directly, the initial response was that RFC
0959 and 1123 require all FTP servers to implement RNFR/RNTO.  But when I read
these RFCs, I see that an FTP server *doesn't* have to implement things that
an OS doesn't support (duh).  I can also make the case that for security
reasons you might explicitly prevent FTP server support for certain write-mode
operations like RNFR/RNTO.

Regardless of the RFC issue, this MPE client change violates the Principle of
Least Astonishment -- i.e. I find it *very* astonishing that the client is
attempting a no-op rename on the server when all I want is just a read-only
download.

For reasons not yet fully explained to me, this RNFR/RNTO stuff has something
to do with 3000<->3000 file transfers, and right now there is just one code
path in the client to deal with both 3000 servers and non-3000 servers.

The lab is presently thinking some more about this approach.  A formal SR
should be entered soon.  In the meantime I have restored my pre-Express3
FTP client and server.

If anybody else is FTP-ing with unusual remote systems, you should definitely
test things after installing Express3.
--
Mark Bixby                      E-mail: [log in to unmask]
Coast Community College Dist.   Web: http://www.cccd.edu/~markb/
District Information Services   1370 Adams Ave, Costa Mesa, CA, USA 92626-5429
Technical Support               +1 714 438-4647
"You can tune a file system, but you can't tune a fish." - tunefs(1M)