DHCP服务脚本

在运行脚本之前需要配置GNS3,可以看我之前的博客有详细教程

#!/bin/bash
yum install dhcp -y  //安装DHCP服务
yum install expect -y  //安装expect工具
/usr/bin/expect <<-EOF    
spawn cp /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example /etc/dhcp/dhcpd.conf  
//spawn追踪后面的命令
expect{    //匹配
        "cp*"  //用“*”代表后面一长串命令
        {send "yes\r"}  //交互式输入yes  '\r’代表回车
}
        expect eof
EOF
cat <<-EOF >> /etc/dhcp/dhcpd.conf   //在DHCP配置文件中写入命令
subnet 192.168.100.0 netmask 255.255.255.0 {    //网段，子网掩码
  range 192.168.100.20 192.168.100.200;    //网段范围
  option routers 192.168.100.1;     //网关
EOF
}
EOF
systemctl stop firewalld.service  //关闭防火墙
setenforce 0    //关闭增强功能
systemctl start dhcpd  //开启DHCP服务