DHCP:Dynamic Host Configuration Protocol 前身：Bootp:无盘工作站
RARP 反向地址解析协议
lease 租约 vim /var/lib/dhcpd/dhcpd.leases
基于UDP 服务器端：67 客户端：68
DHCP Discovery 客户端ip地址请求 DHCP Offer 服务器端提供 DHCP Request 客户端请求 DHCP ACK 服务端响应
release 地址释放 归还，地址到期，关机
续租：
dhcp，dhcpd,dhcre 主配置文件：/etc/dhcpd.conf,/etc/sysconfig/dhcpd dhcpd.conf样例 /usr/share/doc/dhcp-3.0.5/dhcpd.conf.example 启动脚本：/etc/init.d/dhcpd start|stop|status|restart
/etc/sysconfig/dhcpd DHCPDARGS=Eth0
dhcpclient -d dhcpclient eth0 killall dhcpclient
PEERDNS=no
类别定义： class "vmware" { match if substring (hardware,1,3) = 00:0C:29; }
pool { allow members of "vmware"; range 192.168.10.31 192.168.10.40; }
pool { deny members of "vmware"; range 192.168.10.101 192.168.10.200; }
DHCP中继： /etc/sysconfig/dhcrelay INTERFACES="eth1 eth0" DHCPSERVERS="192.168.10.6" service dhcrelay start
