Subject: ftp-gw not passing the "Fin" on data session

From: "Barreira, Fernando [IT]" <[email-masked]>
Date: Tue, 2 Jan 2001 16:08:49 -0500

hi there,

i have fwtk 2.1 on a solaris 5.6 machine, when a user goes to a specific
site (ftp1.lewcosec.com) and does something that triggers a data session(the
"ls" command), the ftp session hungs.
this does not happen every single session but it happens very often that
causes ftp scripts to fail.

on the machine that runs the fwtk, i did capture both sessions, the one
between the client machine and the ftp-gw and between the ftp-gw and the
remote server (ftp1.lewcosec.com).
i noticed on one og the hung sessions, the remote server sends a packet for
the data session with the Fin=1 to terminate the data session and the ftp-gw
never frowards it to the client machine.

why would the ftp-gw sometimes send it and sometimes not?

here are the captures for the the same data session, "client" is the
client<===>ftp-gw connection; "server" is the
ftp-gw<===ftp1.lewcosec.com connection. any help would be appreciated.

  <<client>>  <<server>>