TCP timestamps and ftp.netscape.com

tenthumbs (10@dhyp3-098.cybernex.net)
Mon, 20 Dec 1999 07:09:46 -0500 (EST)


This message is in MIME format. The first part should be readable text,
while the remaining parts are likely unreadable without MIME-aware tools.
Send mail to mime@docserver.cac.washington.edu for more info.

--0-1844159382-945691786=:244
Content-Type: TEXT/PLAIN; charset=US-ASCII

I realize that it is highly unlikely that Linux is at fault but I'm no
expert so I feel I should ask.

The symptoms are simple: passive-mode connections to ftp.netscape.com
fail. Here's an example:

--->ftp
ftp> debug
Debugging on (debug=1).
ftp> passive
Passive mode on.
ftp> open ftp.netscape.com
Connected to ftp.netscape.com.
220 ftp103 SGI 1.5: FTP server (Version wu-2.4.2-academ[BETA-17](20) Sat Jan 23 23:20:31 PST 1999) ready.
---> USER anonymous
331 Guest login ok, send your complete e-mail address as password.
---> PASS XXXX
230-Welcome to the Netscape Communications Corporation FTP server.
230-
230-If you have any odd problems, try logging in with a minus sign (-)
230-as the first character of your password. This will turn off a feature
230-that may be confusing your ftp client program.
230-
230-Please send any questions, comments, or problem reports about
230-this server to ftp@netscape.com.
230-
230-*********** October 13, 1995 **********
230-Private ftp is now only on ftp1.netscape.com. Anonymous is supported on
230-ftp 2 through 8. If you are accessing a named account please use ftp1.
230-
230 Guest login ok, access restrictions apply.
---> SYST
215 UNIX Type: L8
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls
ftp: setsockopt (ignored): Permission denied
---> PASV

It dies here. The same thing happens if I telnet to the server.
Active-mode connections work.

More digging reveals that the server actually does send the PASV
response but 2.2.13 and 2.2.14pre* kernels ignore the packets. If you
turn off tcp timestamps then it works. Attached is a tcpdump of the
above transaction. A raw packet dump is also available.

I'm wondering what goes wrong and where.

Thanks.

--0-1844159382-945691786=:244
Content-Type: TEXT/plain; name="ns-ftp-dump.txt"
Content-Transfer-Encoding: BASE64
Content-ID: <Pine.LNX.4.05.9912200709460.244@perfect.master>
Content-Description:
Content-Disposition: attachment; filename="ns-ftp-dump.txt"
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--0-1844159382-945691786=:244--
-
To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to majordomo@vger.rutgers.edu