I have a Windows 2008 server with IIS7 which I use for FTP server. All working fine, but recently I get follow problems: the IIS7 is set to work in passive mode before 4 months and it work fine until 2 weeks.Now - after download few files, or after few hours or days it stop working in passive mode, but working only in PORT mode. The interesting is that no any human send any action to server. After restart of FTP service or on all Windows 2008 it starts working in passive mode.
What could be the problem and what settings I should do? I check, my settings in firewall are not changed.
This is some bug in Windows 2008? It will help if I go to Win 2008 R2 ?