What is PASV-mode ??
Passive ftp mode - I am not an expert on this, but it has to do with port selection, what port is to be used with ftp. It is supposed to (I think) help make ftp more secure by playing with port #'s (I may be wrong on that). We have firewalled out most ports, so for us PASV mode does not work - the clue is very slow ftp once logon has completed. PASV mode is an option in the ftp client.
How can I check it
Look in your ftp client connection options, what program(s) do you use?
P.S. I am connected with a router to the internet, Other persons are directely connected from there PC to there cable-modem It has ALLWAYS worked. The problems started yesterday evening
Did you ISP make any firewall changes last night? Jale