1，查看防火墙文件：
vim /etc/sysconfig/iptables # Generated by iptables-save v1.4.7 on Thu Jan ::
*filter
:INPUT ACCEPT [:]
:FORWARD ACCEPT [:]
:OUTPUT ACCEPT [:]
-A INPUT -p tcp -m tcp --dport -j ACCEPT
-A INPUT -p tcp -m tcp --dport -j ACCEPT
COMMIT
# Completed on Thu Jan ::
2,添加开发端口：（添加，保存，重启）
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# /sbin/iptables -I INPUT -p tcp --dport -j ACCEPT
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# /etc/rc.d/init.d/iptables save
iptables：将防火墙规则保存到 /etc/sysconfig/iptables： [确定]
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# vim iptables
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# vim iptables
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# /sbin/iptables -I INPUT -p tcp --dport 22 -j ACCEPT
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# /etc/rc.d/init.d/iptables save
iptables：将防火墙规则保存到 /etc/sysconfig/iptables： [确定]
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# service iptables restart
iptables: Setting chains to policy ACCEPT: filter [ OK ]
iptables: Flushing firewall rules: [ OK ]
iptables: Unloading modules: [ OK ]
iptables: Applying firewall rules: [ OK ]
3，查看防火墙状态，开启/关闭防火墙。
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# /etc/init.d/iptables status
表格：filter
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:22
2 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 Chain FORWARD (policy ACCEPT)
num target prot opt source destination Chain OUTPUT (policy ACCEPT)
num target prot opt source destination [root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# chkconfig iptables --list
iptables 0:关闭 1:关闭 2:关闭 3:关闭 4:关闭 5:关闭 6:关闭
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# chkconfig iptables on
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# chkconfig iptables --list
iptables 0:关闭 1:关闭 2:启用 3:启用 4:启用 5:启用 6:关闭
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# chkconfig iptables off
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# chkconfig iptables --list
iptables 0:关闭 1:关闭 2:关闭 3:关闭 4:关闭 5:关闭 6:关闭
4，查看已经开启的端口。
[root@VM-5bb62e30-ecd0-4df8-b26f-9b9a2e4bd5f9 sysconfig]# netstat -tanp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:60222 0.0.0.0:* LISTEN 30288/java
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 6716/mysqld
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 30342/nginx
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1460/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1537/master
tcp 0 0 192.168.0.153:22 61.144.66.28:2109 ESTABLISHED 30009/sshd
tcp 0 0 192.168.0.153:22 113.195.145.85:9582 ESTABLISHED 35585/sshd
tcp 0 0 192.168.0.153:80 14.18.243.92:2911 TIME_WAIT -
tcp 0 0 192.168.0.153:22 14.18.243.92:17216 ESTABLISHED 35091/sshd
tcp 0 0 127.0.0.1:3306 127.0.0.1:48637 ESTABLISHED 6716/mysqld
tcp 0 0 127.0.0.1:3306 127.0.0.1:48635 ESTABLISHED 6716/mysqld
tcp 0 0 127.0.0.1:3306 127.0.0.1:48634 TIME_WAIT -
tcp 0 880 192.168.0.153:22 14.18.243.92:21646 ESTABLISHED 35240/sshd
tcp 0 0 127.0.0.1:3306 127.0.0.1:48639 ESTABLISHED 6716/mysqld
tcp 0 0 127.0.0.1:3306 127.0.0.1:48638 ESTABLISHED 6716/mysqld
tcp 0 0 192.168.0.153:22 14.18.243.92:17485 ESTABLISHED 35528/sshd
tcp 0 0 127.0.0.1:3306 127.0.0.1:48636 ESTABLISHED 6716/mysqld
tcp 0 0 ::ffff:127.0.0.1:8005 :::* LISTEN 30288/java
tcp 0 0 :::8009 :::* LISTEN 30288/java
tcp 0 0 :::8080 :::* LISTEN 30288/java
tcp 0 0 :::22 :::* LISTEN 1460/sshd
tcp 0 0 ::1:25 :::* LISTEN 1537/master
tcp 0 0 ::ffff:127.0.0.1:48638 ::ffff:127.0.0.1:3306 ESTABLISHED 30288/java
tcp 0 0 ::ffff:127.0.0.1:48639 ::ffff:127.0.0.1:3306 ESTABLISHED 30288/java
tcp 0 0 ::ffff:127.0.0.1:48629 ::ffff:127.0.0.1:3306 TIME_WAIT -
tcp 0 0 ::ffff:127.0.0.1:48636 ::ffff:127.0.0.1:3306 ESTABLISHED 30288/java
tcp 0 0 ::ffff:192.168.0.153:8080 ::ffff:14.18.243.92:11473 TIME_WAIT -
tcp 0 0 ::ffff:127.0.0.1:48637 ::ffff:127.0.0.1:3306 ESTABLISHED 30288/java
tcp 0 0 ::ffff:127.0.0.1:48633 ::ffff:127.0.0.1:3306 TIME_WAIT -
tcp 0 0 ::ffff:127.0.0.1:48628 ::ffff:127.0.0.1:3306 TIME_WAIT -
tcp 0 0 ::ffff:127.0.0.1:48635 ::ffff:127.0.0.1:3306 ESTABLISHED 30288/java