vi /etc/vsftpd/vsftpd.conf

pasv_enable=YES
pasv_min_port=60000
pasv_max_port=60001
pasv_address=x.x.x.x

vi /etc/pure-ftpd/pure-ftpd.conf

Bind                            z.z.z.z,10021

PassivePortRange          60010 60011

ForcePassiveIP x.x.x.x

vi nginx.conf

stream {
#FTP
upstream ftp {
hash $remote_addr;
server z.z.z.z:21 weight=5 max_fails=3 fail_timeout=30s; #v
server z.z.z.z:10021 weight=5 max_fails=3 fail_timeout=30s; #p
}

server {
listen 20021;
proxy_connect_timeout 1s;
# proxy_timeout 3s;
proxy_pass ftp;
}

#FTP data
upstream ftpdata-v1 {
server z.z.z.z:60000 weight=5 max_fails=3 fail_timeout=30s;
}
upstream ftpdata-v2 {
server z.z.z.z:60001 weight=5 max_fails=3 fail_timeout=30s;
}
upstream ftpdata-p1 {
server z.z.z.z:60010 weight=5 max_fails=3 fail_timeout=30s;
}
upstream ftpdata-p2 {
server z.z.z.z:60011 weight=5 max_fails=3 fail_timeout=30s;
}

# vsftpd
server {
listen 60000;
proxy_connect_timeout 1s;
proxy_timeout 3s;
proxy_pass ftpdata-v1;
}
server {
listen 60001;
proxy_connect_timeout 1s;
proxy_timeout 3s;
proxy_pass ftpdata-v2;
}

# pure-ftpd
server {
listen 60010;
proxy_connect_timeout 1s;
proxy_timeout 3s;
proxy_pass ftpdata-p1;
}
server {
listen 60011;
proxy_connect_timeout 1s;
proxy_timeout 3s;
proxy_pass ftpdata-p2;
}