I got an app which uses FTP from a WinXP Client to an RedHat62 Linux Server. Deactivating the FW of WinXP SP2 everything goes fine. Activating the FW and setting this app as trusted, the FTP session doesn't work correctly.
The fine, but evident difference is, that on closing the FTP Session (after transferring all the data) the app sends [RST, ACK] with firewall acive and [FIN, ACK] when firewall is off. And sending [RST, ACK] doesn't close the session and it repeats until app's timeout.
Using annother firewall like the "tiny" one, the were no problems. But our customers could not change the FW , cause of their IT-Audits.
So I have to solve the problem. Does anybody know why windows XP SP2 firewall does change this flag from [FIN, ACK] to [RST, ACK] in the TCP/IP communication?
any advice is appreciated!