ポート80が開いているかどうかはどうすればわかりますか？

コンピュータを保存して再起動します。 iptablesファイルを見ると、次の内容が含まれています。

[root@server /]# cat /etc/sysconfig/iptables
# Generated by iptables-save v1.4.21 on Sat Feb 24 15:25:25 2018
*raw
:PREROUTING ACCEPT [4:164]
:OUTPUT ACCEPT [3:120]
COMMIT
# Completed on Sat Feb 24 15:25:25 2018
# Generated by iptables-save v1.4.21 on Sat Feb 24 15:25:25 2018
*nat
:PREROUTING ACCEPT [3:124]
:POSTROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
COMMIT
# Completed on Sat Feb 24 15:25:25 2018
# Generated by iptables-save v1.4.21 on Sat Feb 24 15:25:25 2018
*mangle
:PREROUTING ACCEPT [4:164]
:INPUT ACCEPT [4:164]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [3:120]
:POSTROUTING ACCEPT [3:120]
COMMIT
# Completed on Sat Feb 24 15:25:25 2018
# Generated by iptables-save v1.4.21 on Sat Feb 24 15:25:25 2018
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
COMMIT
# Completed on Sat Feb 24 15:25:25 2018

私のコンピュータから私のWebサーバーにアクセスできますが、

[root@server tmp]# wget "http://my_ip_address/"
--2018-02-24 15:28:38--  http://my_ip_address/
Connecting to my_ip_address:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3700 (3.6K) [text/html]
Saving to: 'index.html.6'

100%[======================================================================================================>] 3,700       --.-K/s   in 0s

2018-02-24 15:28:38 (470 MB/s) - 'index.html.6' saved [3700/3700]

まだ外部から接続できませんね。他のものはそれを防いでいます。他に何を確認するのか、iptablesを正しく設定したのかわかりません。