Re: [fw-wiz] Slow FTP transfers

I've had a similar problem twice.

The first time we had a bad network cable that was causing repeated resends due to a short. This sometimes caused timeouts if a file couldn't be transferred within a certain amount of time

The second time we had a wireless T1 that was being blocked by a tree. Small files came across, but large files would sometimes time out. Not always, though, due to the fact that the tree's leaves would blow in the wind or be still.

Both issues were basically the same. Frequent packet errors which cause retransmits and eventually timeouts when the sending computer does not get a response. It taught me to never overlook the basics!

Bill O'Connell Network Solution Manager
Liberty Creative Solutions, Inc.
18625 West Creek Dr. | Tinley Park, IL 60477
V: (708) 633-7450
F: (708) 633-7449

From: firewall-wizards-bounces@xxxxxxxxxxxxxxxxxxxxxxx [mailto:firewall-wizards-bounces@xxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Farrukh Haroon
Sent: Tuesday, August 25, 2009 2:50 AM
To: Firewall Wizards Security Mailing List
Subject: Re: [fw-wiz] Slow FTP transfers

Your problem could be due to your firewall blocking the IDENT protocol

Have a look at this link:

It could also be related to PTR records for your DIP Pool (but highly unlikely):


On Mon, Aug 24, 2009 at 7:26 PM, Francois Yang <francois.y@xxxxxxxxx<mailto:francois.y@xxxxxxxxx>> wrote:
I've seen slow traffic due to the firewall trying to do many things
like checking for viruses, packet anomalies, etc...
Maybe there's some checks that works better or worst depending if the
ftp session is passive or not.


On Fri, Aug 21, 2009 at 7:43 AM, Behm, Jeff<jbehm@xxxxxxxxxxxx<mailto:jbehm@xxxxxxxxxxxx>> wrote:
On Thursday, August 20, 2009 12:19 PM, sky said:

I'm having an issue when ftp'ing (default port mode) large file
(50megs) to a remote server sitting behind FWSM. The transfer
gets real slow and at times just timeouts.

Any thoughts will be great.

Any sort of packet shaper/QoS device between the endpoints?
firewall-wizards mailing list

If you spend more on coffee than on IT security, you will be hacked.
What's more, you deserve to be hacked. - White House Cybersecurity
Advisor, Richard Clarke
firewall-wizards mailing list

This message has been scanned for viruses and
dangerous content by OpenProtect<>, and is
believed to be clean.

This message has been scanned for viruses and
dangerous content by OpenProtect(, and is
believed to be clean.

firewall-wizards mailing list