FTP Not Working On Port 21

Date: 10/27/2015, Author: Lostwake, Category: Virtualmin & Server Tips

My server stopped allowing users to login to FTP through port 21 and only allowed port 22 and SFTP.

After a lot of digging I found the solution by loading the FTP connection tracking module on the server.

This can be done by logging into Putty and running the command:

modprobe ip_conntrack_ftp

I found this answer on this thread: http://www.cloudmin.com/node/34246

An it pointed me to this Virtualmin Documentation: https://www.virtualmin.com/documentation/web/faq#FTP_Service_isn-t_working

Hope this helps everyone.