I've installed vsftpd on my computer with Gentoo Linux. I'm connecting to it from localhost. There seems to be nothing wrong with networking or privileges, since I can log into the ftp server and change the current directory. However, when I try to use "ls", "get" or "put", the ftp client claims error 421 Service not available. Here's an example:
╭─ag@AprilGrimoire ~
╰─$ ftp 127.0.0.1
Connected to 127.0.0.1.
220 Welcome to blah FTP service.
Name (127.0.0.1:ag):
530 Please login with USER and PASS.
530 Please login with USER and PASS.
SSL not available
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd OI
250 Directory successfully changed.
ftp> cd 2019
250 Directory successfully changed.
ftp> ls
200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
500 OOPS: 421 Service not available, remote server has closed connection
ftp> %
