Due to the limitation of IPv4 in my campus. I need an IPv6 FTP server to share files(e.g. teacher's PPT, experiment video) among my class. Vsftpd, proftpd or pureftpd any of them is fine. But, I don't know how to set them to use IPv6. Would anybody like to teach me? Appreciate a lot.
In most cases, there isn't any reason to set up an FTP server as your droplet will already have SSH running, allowing you to connect via SFTP by default.
FileZilla should support connecting to SFTP via IPv6 with the server's username and password. The port field will be 22. In the host field, use the IPv6 address assigned to your droplet. This can be found in the droplet's Settings tab in the DigitalOcean control panel. The address should be in between brackets, like:
[2404:6800:4003:803::1006]
Of course, your local network will need to support IPv6 as well. You can test that using this site.
Let us know how it goes!
I mean how set an IPv6 ftp server on my VPS, but not how to use a client to connect ftp server.
I believe ProFTPd listens on all interfaces/addresses, including IPv6, by default. Here's a HowToForge tutorial on installing ProFTPd on CentOS 7: How to install ProFTPD on CentOS 7.0,