即使打开了所需端口，filezilla 也无法连接

Question

服务器：Ubuntu 15.04-2.6.32-042stab094.8

客户端：Windows 10

我对 iptables 做了一些更改，保存了所有规则，当然，之后又重新应用了它们，更改总结如下：

开放端口

• TCP：20、21、22、43、443
• UDP：123

默认政策

• 输入-放下
• 转发—接受
• 输出-接受

在更改之前，默认输入被接受，因此 filezilla 连接等。在删除所有传入（除指定的传入）后，FZ 无法连接

FZ使用SFTP协议正常登录

我是否缺少 sftp 连接所需的端口？

更新

过滤表

sudo iptables -L -t filter

Chain INPUT (policy DROP)
target     prot opt source               destination         
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ftp-data /* FTP-Data IN (iface:ALL) */
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ftp /* FTP-Ctrl IN (iface:ALL) */
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh /* SSH IN (iface:ALL) */
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:whois /* Whois IN (iface:ALL) */
ACCEPT     udp  --  anywhere             anywhere             udp dpt:ntp /* NTP IN (iface:ALL) */
ACCEPT     icmp --  anywhere             anywhere             /* Ping Request/Reply IN (iface:ALL) */

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere            

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     icmp --  anywhere             anywhere             /* Ping Request/Reply OUT (iface:ALL) */

Chain LOGGING (0 references)
target     prot opt source               destination

NAT 表

sudo iptables -L -t nat


Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination         
SNAT       all  --  anywhere             anywhere             to:x.x.x.x <- server ip
MASQUERADE  all  --  10.0.0.0/24          anywhere            

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination