我在 Ubuntu 18.04 LTS 上安装了 VSFTPD，无法从公共 IP 连接。这是我的配置：
listen=YES
listen_ipv6=NO
anonymous_enable=NO
local_enable=YES
write_enable=YES
local_umask=022
dirmessage_enable=YES
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_file=/var/log/vsftpd.log
xferlog_std_format=YES
secure_chroot_dir=/var/run/vsftpd/empty
pam_service_name=vsftpd
userlist_file=/etc/vsftpd.userlist
userlist_deny=NO
chroot_local_user=YES
allow_writeable_chroot=YES
user_sub_token=$USER
local_root=/media/veracrypt4
rsa_cert_file=/etc/ssl/certs/vsftpd.crt
rsa_private_key_file=/etc/ssl/private/vsftpd.key
ssl_enable=YES
ssl_tlsv1=YES
ssl_sslv2=YES
ssl_sslv3=YES
allow_anon_ssl=NO
force_local_data_ssl=YES
force_local_logins_ssl=YES
ssl_ciphers=HIGH
pasv_enable=YES
#pasv_address=xxx.xxx.xxx.xxx
#pasv_addr_resolve=YES
pasv_min_port=40000
pasv_max_port=50000
我配置了 iptables
-P INPUT DROP
-P FORWARD DROP
-P OUTPUT ACCEPT
-N f2b-postfix
-A INPUT -p tcp -m multiport --dports 80,443,25,587,465,110,995,143,993,4190 -j f2b-postfix
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 25 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 587 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 110 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 995 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 143 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 993 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 21 -m conntrack --ctstate NEW -j ACCEPT
-A INPUT -p udp -m udp --dport 137 -j ACCEPT
-A INPUT -p udp -m udp --dport 138 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 139 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 445 -j ACCEPT
-A INPUT -s 192.168.1.0/24 -p udp -m udp --dport 137 -j ACCEPT
-A INPUT -s 192.168.1.0/24 -p udp -m udp --dport 138 -j ACCEPT
-A INPUT -s 192.168.1.0/24 -p tcp -m tcp --dport 139 -j ACCEPT
-A INPUT -s 192.168.1.0/24 -p tcp -m tcp --dport 445 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 21 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 20 -j ACCEPT
-A INPUT -p tcp -m multiport --dports 20,21,40000:50000 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 20 -m conntrack --ctstate NEW -j ACCEPT
-A INPUT -p tcp -m tcp --dport 21 -m conntrack --ctstate NEW -j ACCEPT
-A INPUT -p tcp -m tcp --dport 990 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 989 -j ACCEPT
-A OUTPUT -p tcp -m tcp --sport 20 -j ACCEPT
-A f2b-postfix -s xx.x.xxx.x/32 -j REJECT --reject-with icmp-port-unreachable
-A f2b-postfix -j RETURN
-A f2b-postfix -j RETURN
这是我的路由器配置：
https://i.stack.imgur.com/qX8hH.jpg
仍然无法连接，只出现 500 POST 错误或登录错误。本地连接运行良好。非常感谢您的帮助！