你可以用rpm -qa | grep iptables來查看,centos7預設防火牆是firewalld,iptables應該是沒有安裝,你可以用yum install iptables -y來安裝。
1、關閉firewall:
systemctl stop firewalld.service #停止firewall
systemctl disable firewalld.service #禁止firewall開機啟動
2、安裝iptables防火牆
yum install iptables-services #安裝
3
接下來的事情就和用iptables是一樣的了,若要開啟某連接埠,則(80連接埠為例,紅色為添加的規則)(
有先後順序):
vi /etc/sysconfig/iptables
-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT #允許80連接埠通過防火牆
############################## 添加後 防火牆規則如下所示 ##############################
# 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
重啟服務
systemctl restart iptables
systemctl enable iptables.service #設定防火牆開機啟動