IP Masq 2.0.28 - Large ftp downloads hang on netscape3/4 NT/Linux

IP Masq 2.0.28 - Large ftp downloads hang on netscape3/4 NT/Linux

Post by Nicolas Scharnag » Tue, 04 Mar 1997 04:00:00



The ip_masq_ftp module is installed on the fw and
it usually works for small downloads.

On the fw, the problem is not present.
The download window hangs when it has reached 100%.
With netstat , the client seems to think the connection is
still open but it does not send out anymore packets visible
with tcpdump on the masq'd machine.

I remember similar problems with Netscape 1.1 long time ago

 
 
 

IP Masq 2.0.28 - Large ftp downloads hang on netscape3/4 NT/Linux

Post by Dimitrios P. Boura » Tue, 04 Mar 1997 04:00:00



> The ip_masq_ftp module is installed on the fw and
> it usually works for small downloads.

> On the fw, the problem is not present.
> The download window hangs when it has reached 100%.
> With netstat , the client seems to think the connection is
> still open but it does not send out anymore packets visible
> with tcpdump on the masq'd machine.

  This is due to timeout of the tcp connection employed by ftp. Try
 increasing the timeout value for tcp connections using (a variation
 of):

    ipfwadm -M -s 3600 0 0

 In the above example (see the man page for details) the timeout is
 set to 60 minutes - can't remember what the default is and can't find
 it in the man page :)

  Hope the above helps,

  Dimitri

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IP Masq 2.0.28 - Large ftp downloads hang on netscape3/4 NT/Linux

Post by Ken Ev » Tue, 11 Mar 1997 04:00:00


: The ip_masq_ftp module is installed on the fw and
: it usually works for small downloads.

: On the fw, the problem is not present.
: The download window hangs when it has reached 100%.
: With netstat , the client seems to think the connection is
: still open but it does not send out anymore packets visible
: with tcpdump on the masq'd machine.

: I remember similar problems with Netscape 1.1 long time ago

The problem may be that masq has timed out the control connection.

FTP uses 2 connections. . . 1 for data, the other for control.

When you do a long download, the control connection is idle.  Masq figures
you are gone, and disconnects the control connection.  Once the data
connection finishes, you hang.

There is a great masq site and documentation, but I don't remember the
URL.  You can find it by going to http://sunsite.unc.edu/linux and looking
for a link to the masq howto.

ttyl,

Ken Eves