Re: FTP to fast -- MIDRANGE-L

Thanks Don. Solid info. We'll see where it goes.
Regards,Laura

Laura Ubelhor

President

Consultech Services, Inc.

Office: (248) 628-6800

ubelhor@xxxxxxxxxxxxx | www.consultechservicesinc.com

On Thursday, February 3, 2022, 05:58:22 PM EST, Don Brown via MIDRANGE-L <midrange-l@xxxxxxxxxxxxxxxxxx> wrote:

I would suggest that when they have "fixed" the crash they have installed
a new ftp server.

ftp has two modes - Active and Passive.

Very simplified they work like this;

Port 21 on the FTP Server is for the Command Channel
Port 20 or a random port on the FTP Server is used for the Data channel,
depending on the mode Active or Passive.

Active
FTP Client on random port initiates connection to server on Port 21
The PORT command is sent specifying what Client Side port the server
should connect to
FTP Server on port 20 connects to the client on the designated port (As
advised by the client)

Passive
FTP Client on random port initiates connection to the server on port 21
The PASV command is sent.
FTP Server responds with the random port to be used
FTP Client on random port connects to FTP Server on random port issued by
the FTP Server

The above is very simplified and is excluding ACK replies etcetera

From the log you provided it appears the mode is Active, you would be

better using Passive.
The log shows;
You are connected to the FTP Server
You can enter commands - This uses the Command channel on port 21
As soon as you try and use the Data channel it times out
This proves there is not communication on the Data channel

To solve the issue
Confirm the connection is using Passive
Confirm what ports are being used for the passive data connection. The
people responsible for the FTP server will need to advise this.
Ensure the passive data ports are allowed out through your firewall. And
that they are allowing all the passive ports in!!

One quick way to do this is a get a trace of the ftp session and you will
be able to see the packet flow.

My 2 cents.

Don

From: "Laura Ubelhor" <ubelhor@xxxxxxxxxxxxx>
To: "midrange-l@xxxxxxxxxxxxxxxxxx" <midrange-l@xxxxxxxxxxxxxxxxxx>
Date: 04/02/2022 03:54 AM
Subject: Re: FTP to fast
Sent by: "MIDRANGE-L" <midrange-l-bounces@xxxxxxxxxxxxxxxxxx>

Hello:
I don't believe so.
The weird thing is the FTP worked for several years. They had a network
server crash and it stopped. Of course on the network side they are not
being very helpful. They came up with slow the data transfer down
response, They finally shared a log but have not been real helpful.
The weird thing is if you send the file manually it works just fine.
If you send it automatically (which worked for years) it does not.
The ids are the same the ports the same. I really think it is on the
network side.

What do you think about this response from midrange

"Unable to setup for an active data connection to the server reason code

Passive FTP is all driven by the client.
Active FTP requires the remote server to open a second socket connection
back to the client.
No doubt the enterprise firewall prevents such an action.

If I understand by what I see on the logs the Passive is the manual send
which works.
The active is the batch that does not.
Does you think this is accurate? Does active require a second socket
connection back to the client?
Thanks for jumping in. Cindy is working on this and is quite frustrated.
It's the usual conversation the network group is not being very helpful
although it happened after the server went down (crashed we hear) and
after it was back up. The server is used to collect feeds from around
the world and resides in Germany. I have no insight into whether other
transfers are crashing although I have asked.
It's a winter wonderland here in Michigan. Very pretty but not much
outside activity. It looks like we got about a foot of snow.
Hope you're doing well.
ThanksRegards,Laura

Laura Ubelhor

President

Consultech Services, Inc.

Office: (248) 628-6800

ubelhor@xxxxxxxxxxxxx | www.consultechservicesinc.com

On Thursday, February 3, 2022, 12:07:27 PM EST, Richard Schoen
<richard@xxxxxxxxxxxxxxxxx> wrote:

Maybe I missed this but have you tested the FTP with something like
FileZilla ?

Regards,
Richard Schoen
Web: http://www.richardschoen.net
Email: richard@xxxxxxxxxxxxxxxxx
----------------------------------------------------------------------

message: 1
date: Thu, 3 Feb 2022 09:48:22 -0700
from: Jack Woehr via MIDRANGE-L <midrange-l@xxxxxxxxxxxxxxxxxx>
subject: Re: FTP to fast

On Thu, Feb 3, 2022 at 9:43 AM Laura Ubelhor <ubelhor@xxxxxxxxxxxxx>
wrote:

"Unable to setup for an active data connection to the server reason code

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