I tried to open the file with\\192.168.0.2\abc\def.txt
You are accessing the FTP service of the B server, and it has nothing to do with the asp.net user permissions. You try to set the FTP directory to be fully shared.
You cannot open the file with\\192.168.0.2\abc\def.txt
The reason is that there is no permission added, this should be accessible as per what I said above.
But how do you access it in the code? Best post code to see
With the simplest test,
For example, write a probe file in C # to detect the existence of System.IO.File.Exist (filename),
Or create a folder CreateDirectory (dir_name); ...
Written in C #
Probe\\192.168.0.2\abc\def.txt