dhcp-server配置：
enable
conf t
interface F0/1
ip address 192.168.1.100 255.255.255.0   ----------------------------配置DHCP服务器IP地址
no shutdown
exit
ip dhcp pool abc                        --------------------------配置地址池
network 192.168.1.0 255.255.255.0      --------------允许分配网段地址
default-router 192.168.1.1             -----------------默认网关
dns-server 202.19.1.244                --------------------DNS服务器
exit
ip dhcp excluded-address 192.168.1.0 192.168.1.100            -------------不允许分配这些地址给主机
end