Introducing NOP on command PORT

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Introducing NOP on command PORT

#1 Post by POLAURENT » 2020-09-21 19:35

Hello everybody,

i'm facing a problem that i never have met before, but my request may be an interresting feature:

Starting a big file transfer with a Android device ( makes the same with the basic ftp windows client) , the transfer is never completed.

The reason is that the firewall or router between closes the command port during the data transfer, cause there is no activity on it ( it's not in RFC but that the way it acts).

at the end of the transfer, the client can not acknowlege the reception cause the command link is closed.

As far as it's impossible to modify the Client itself, may be it possible to introduce a NOP response or something else from the server to the client to make the command link active , or a TCP packet ?

thanks for your answer

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Re: Introducing NOP on command PORT

#2 Post by botg » 2020-09-22 06:54

Please don't cross-post, that's rude. Question has already been answered on a different channel.