我通过iptables打开了端口443：

pkts bytes target prot opt in out source destination

45 2428 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0

6 1009 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80

141 10788 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22

0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80

0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:443

7 1140 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED

6 360 DROP all -- * * 0.0.0.0/0 0.0.0.0/0

它正在监听netstat -a表示：

Proto Recv-Q Send-Q Local Address Foreign Address State

tcp 0 0 *:6311 *:* LISTEN

tcp 0 0 *:ssh *:* LISTEN

tcp 0 0 gauss:ssh ommited ESTABLISHED

tcp 0 0 gauss:ssh ommited ESTABLISHED

tcp6 0 0 localhost:8005 [::]:* LISTEN

tcp6 0 0 [::]:8009 [::]:* LISTEN

tcp6 0 0 [::]:www [::]:* LISTEN

tcp6 0 0 [::]:ssh [::]:* LISTEN

tcp6 0 0 [::]:https [::]:* LISTEN

udp 0 0 *:mdns *:*

udp 0 0 *:52703 *:*

udp6 0 0 [::]:42168 [::]:*

udp6 0 0 [::]:mdns [::]:*

但是我不能ping端口443：

PING 443 (0.0.1.187) 56(124) bytes of data.

^C

--- 443 ping statistics ---

7 packets transmitted,0 received,100% packet loss,time 6006ms

这是怎么回事？