TCP flag: RST

[saimike]

while doing multiple downloads from a FTP server, i noticed that the server sent a RST during the 3-way handshake to initiate the ftp-data port (not sure if i got this correct, but its the port which the file i'm trying to get will be sent through). this happened after the client sent the SYN,ACK ...

does anyone know what are some of the reasons this would happen?

 

[spidey07]

most likeley a firewall or access list. Or it only allows so many connections from an IP address on the data channel.

 

[saimike]

i presume this would be hard to troubleshoot from the ftp client side?

 

[Garion]

It sounds like you're trying to use Active FTP, where there is a new TCP connection established to deliver the file. Try to find a way to sent your FTP client to passive mode, where the same TCP connection that controls the session is used to transfer data. It's a lot cleaner and better supported in modern networks.

- G

 

[shamans]

And the real answer is....

You're either...
a) Initiating too many tcp connections at one time period...
b) Limited to the # of tcp connections you can establish...
c) You've been temporarily banned at the tcp-level for doing (a).

They don't want you pounding on the ftp server (by being greedy).

 

[saimike]

garion, good suggestion. i will try that.

shamans, when i try downloading a 1MB file, i can do it 50times without issue. but this issue comes up during a 5MB download. perhaps it might not be tcp related?