I'm getting this error in Putty: Server unexpectedly closed network connection Anyone knows how to fix it? All search results show to turn off UseDNS no but I'm not even using dns. I connect to IP directly. Anyway, tried that and it didn't work. I'm able to connect from other locations. just one computer got blocked. I can't find anything in logs, tried to reinstall ssh, ssh-openserver, fail2ban. I'm on Debian Lenny installed using Perfect Server manual.