1.
CentOS6使用的是firewall防火墙
1. 打开配置文件
[root@localhost ~]# vi /etc/sysconfig/iptables
2. 正确的配置文件
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state –state NEW -m tcp -p tcp –dport 22 -j ACCEPT
-A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT
-A INPUT -j REJECT –reject-with icmp-host-prohibited
-A FORWARD -j REJECT –reject-with icmp-host-prohibited
COMMIT
-A INPUT -m state –state NEW -m tcp -p tcp –dport * -j AC
3. 新开启的端口 一定要在22端口的后面写
重启防火墙 使配置生效
[root@localhost ~]# /etc/init.d/iptables restart
查看开放的端口
[root@localhost ~]# /etc/init.d/iptables status
关闭防火墙
[root@localhost ~]# /etc/init.d/iptables stop
2.
CentOS7使用的是firewall防火墙，不再是原来的iptables
1：查看firewall防火墙状态
firewall-cmd --state
或者
systemctl status firewalld
2：打开防火墙
systemctl start firewalld
3：关闭防火墙
systemctl stop firewalld
4：重启防火墙
firewall-cmd --relaod
或者
systemctl reload firewalld
5：开机自启动防火墙
systemctl enable firewalld
6：禁止开机启动防火墙
systemctl disable firewalld
6：查看已打开的端口
firewall-cmd --list-ports
7：打开端口
firewall-cmd --permanent --zone=public --add-port=8080/tcp
其中permanent表示永久生效，public表示作用域，8080/tcp表示端口和类型
8：关闭端口
firewall-cmd --permanent --zone=public --remove-port=8080/tcp
