I am having a weird issue that I can only explain as a possible "port 21 hijack". For some reason, I cannot connect to any ftp sites. The original one I tried was ftp.maltedmedia.com. Filezilla couldn't connect and then I tried several other, all of which can't connect.
I then opened a command prompt window and tried to telnet ftp.maltedmedia.com 21. The screen cleared and when I hit a key, the connection just broke. So it was getting like an empty response.
I do have a local FTP server running on my machine and I can connect to that just fine. When I type telnet localhost 21 in the command window, the screen clears, my welcome message is displayed and I can issue FTP commands to the server just like normal.
Whatever is going on, it seems to be only affecting FTP. My internet and web browsing work just fine.
I tried disabling my antivirus and disabling my firewall. Some thing. Does anyone have any idea what this could be or how I can trace what program, if any, is blocking this.
This is a Windows 7 machine, by the way, using Filezilla as the ftp client.