1、ifconfig命令找不到

　　解决方法：安装net-tools.x86_64工具包   yum install net-tools.x86_64

2、iptables无法使用

　　解决方法：yum install iptables-services

vi /etc/sysconfig/iptables #配置防火墙参数

# sample configuration for iptables service
# you can edit this manually or use system-config-firewall
# please do not ask us to add additional ports/services to this default configuration
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT

:wq! #保存退出

systemctl restart iptables.service #最后重启防火墙使配置生效

systemctl enable iptables.service #设置防火墙开机启动

Centos 7.5配置网络