Re: FTP error using a MAC

Hi Bernard

Now you have totally confused me!

We were running passive mode as the MAC and the PC (same subnet) are behind a firewall, you then told me to change to active mode?

It is my understanding that;
Active Mode;
In active mode the FTP client connects from a random unprivileged port N which is greater then 1023 to the FTP server's command port, port 21.
Then, the client starts listening to port N+1 and sends the FTP command PORT IP,N+1 to the FTP server.
The server will then connect back to the client's specified IP on data port N+1 from its local data port (20)

With active mode the connection fails as the IP address issued is the local IP (private) address behind the firewall

Passive Mode;
In order to resolve the issue of the server initiating the connection to the client a different method for FTP connections was developed, passive mode, or PASV.
In passive mode FTP the client initiates both connections to the server, solving the problem of firewalls filtering the incoming data port connection to the client from the server.
When opening an FTP connection, the client opens two random unprivileged ports locally (N > 1023 and N+1). The first port contacts the server on port 21, but instead of then issuing a PORT command and allowing the server to connect back to its data port, the client will issue the PASV command. The result of this is that the server then opens a random unprivileged port (P > 1023) and sends the PORT P command back to the client. The client then initiates the connection from port N+1 to port P on the server to transfer data.

Both PC and MAC on same subnet using same gateway and hence same firewall

FTP commands
http://www.nsftools.com/tips/RawFTP.htm#PORT

Microsoft FTP commands
http://www.nsftools.com/tips/MSFTP.htm


Regards
Kevin

"Bernard Cheah [MVP]" <qbernard@xxxxxxxxxxxxxxxxxxx> wrote in message news:O5qj0grxIHA.4492@xxxxxxxxxxxxxxxxxxxxxxx
Mm.. funny, per this kb
http://support.microsoft.com/?id=281193

7 x 256 + 192 = 1984
the KB is saying NAT issue.

ftp.exe on windows works? any firewall in between?
the mini mac and other remote windows on same subnet ?


--
Regards,
Bernard Cheah
http://www.iis.net/
http://msmvps.com/blogs/bernard/


"Kevin" <msnewsgroup@xxxxxxxxxxxx> wrote in message news:CD2E9E59-D137-4868-9A81-90FA9CC3E4AA@xxxxxxxxxxxxxxxx
Hi Bernard

No we are using the default port on the web server and as such the initial communication from the MAC is via port 21.

Regards
Kevin

"Bernard Cheah [MVP]" <qbernard@xxxxxxxxxxxxxxxxxxx> wrote in message news:e9LH%23YfxIHA.1440@xxxxxxxxxxxxxxxxxxxxxxx
Did you change the default ftp port other than 21 ?

--
Regards,
Bernard Cheah
http://www.iis.net/
http://msmvps.com/blogs/bernard/


"Kevin" <msnewsgroup@xxxxxxxxxxxx> wrote in message news:%23v3legVxIHA.1936@xxxxxxxxxxxxxxxxxxxxxxx
Hi Bernard

Thank you for your response.

If we switch to active mode then the port command fails as the IP address issued is the local IP associated with the miniMac running behind a firewall, the same firewall as the windows PC;

PORT 121,1,168,192,7,192
500: Invalid PORT command.

Regards
Kevin


"Bernard Cheah [MVP]" <qbernard@xxxxxxxxxxxxxxxxxxx> wrote in message news:e5id1rTxIHA.2188@xxxxxxxxxxxxxxxxxxxxxxx
Errr. how about change the mac client to use active mode?
it looks like passive mode failed.

also I have seen everything is working fine with Wintel machines but not for Mac even for active mode :)

--
Regards,
Bernard Cheah
http://www.iis.net/
http://msmvps.com/blogs/bernard/


"Kevin" <msnewsgroup@xxxxxxxxxxxx> wrote in message news:eGtpCzIxIHA.4912@xxxxxxxxxxxxxxxxxxxxxxx
We are using a miniMAC [Mac OS X 10.4.11 (852167) Darwin 8.11.1] and
attempting to FTP to a Microsoft Windows 2003 (Web Edition) FTP Server
published via ISA 2000.

We can access the FTP server via a Windows PC using WS_FTP, windows explorer
or the command line FTP however when attempting to FTP from the miniMAC we
get errors;

Using OneButton FTP the transcript from the session was as follows;
220: Microsoft FTP Service

USER *******

331: Password required for *******.

PASS xxx

230: ******* FTP Server

User ******* logged in.

PWD

257: "/" is current directory.

PWD

257: "/" is current directory.

PWD

257: "/" is current directory.

CWD .

250: CWD command successful.

PASV

227: Entering Passive Mode (*,*,*,*,16,75)

LIST -a

426: Connection closed; transfer aborted.

LIST

150: Opening ASCII mode data connection for /bin/ls.

425: Can't open data connection.


Does anyone know what is going wrong here or how we can troubleshoot this
issue?

Regards
Kevin









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