1. Open firewall. edit /etc/config/firewall
config rule
option name FTP20-Externaly
option src wan
option proto tcp
option dest_port 20
option target ACCEPT config rule
option name FTP21-Externaly
option src wan
option proto tcp
option dest_port 21
option target ACCEPT
2. Install vsftpd
opkg update
opkg install vsftpd
3. Create the ftp directory
mkdir -p /home/ftp_user
4. add the user to the system - editing /etc/passwd
ftp_user:x:1000:55::/home/ftp_user:/bin/false
5. Change password for ftp_user
passwd ftp_user
6. Configure vsftpd - edit /etc/vsftpd.conf
anonymous_enable=YES
anon_root=/home/ftp_user/
chroot_local_user=YES
7. start/enable/reload
/etc/init.d/vsftpd enable