Problem creating FTPClient after XP Service Pack 2

Question

I've been using edtFTPnet for a while with great results. Then, after installing Windows XP Service Pack 2, I can no longer create an FTPClient without getting this error:

System.Net.Sockets.SocketException: An established connection was aborted by the software in your host machine
at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
at EnterpriseDT.Net.Ftp.FTPControlSocket.Initialize(IPAddress remoteAddr, Int32 controlPort, StreamWriter log, Int32 timeout) in C:\Product Projects\edtFTPnet 1.0.1\FTPControlSocket.cs:line 202
at EnterpriseDT.Net.Ftp.FTPControlSocket..ctor(String remoteHost, Int32 controlPort, StreamWriter log, Int32 timeout) in C:\Product Projects\edtFTPnet 1.0.1\FTPControlSocket.cs:line 152
at EnterpriseDT.Net.Ftp.FTPClient..ctor(String remoteHost) in c:\product projects\edtftpnet 1.0.1\ftpclient.cs:line 234
...

As you can see in the error, I've upgraded to 1.0.1 to see if this would help.

Oh, and I verified that the FTP site is working, my personal firewall is disabled, command line FTP works and IE FTP works.

Thanks for any help
Curt

Answer 1

This seems to be a frequent problem with XP users - not just for FTP but all types of socket operations. An MS bug?

The error is WSAECONNABORTED (10053) Software caused connection abort.

From the Microsoft reference:

Answer/Solution: A connection abort was caused internal to your host machine. The software caused a connection abort because there is no space on the socket's queue and the socket cannot receive further connections.

WinSock description: The error can occur when the local network system aborts a connection. This would occur if WinSock aborts an established connection after data retransmission fails (receiver never acknowledges data sent on a datastream socket).

TCP/IP scenario: A connection will timeout if the local system doesn't receive an (ACK)nowledgement for data sent. It would also timeout if a (FIN)ish TCP packet is not ACK'd (and even if the FIN is ACK'd, it will eventually timeout if a FIN is not returned).

Not much help I'm afraid. One suggestion we've seen is to use the IP address rather than the hostname.

I've been using edtFTPnet for a while with great results. Then, after installing Windows XP Service Pack 2, I can no longer create an FTPClient without getting this error:

System.Net.Sockets.SocketException: An established connection was aborted by the software in your host machine

Answer 2

OK, should have guessed, but even my IT guys are having this kind of trouble and they haven't found this yet. Seems we got an upgrade to McAfee recently. Did I just hear you groan? Yeah, they added a great feature: Port Blocking! On port 21, no less (both inbound and outbound). And, my company doesn't trust us to allow us to turn it off manually, so I haven't been able to verify it. But, I did find a beautiful log file that has several entries in it, even documenting when I tried to FTP and from what application!

Sorry to take your time. I'll let you know if removing this doesn't fix my problem.

Curt