- DHCP:动态主机配置协议,端口:67(server端)/68(client端)
- DHCP安装
# yum install dhcp
Dhcp配置文件目录:/etc/dhcp/
2.1 cat dhcpd.conf
# DHCP Server Configuration file.
# see /usr/share/doc/dhcp*/dhcpd.conf.example
# see dhcpd.conf(5) man page
2.2 修改配置文件/etc/dhcp/dhcpd.conf
subnet 10.252.1.0 netmask 255.255.255.0 {
range 10.252.1.100 10.252.1.200;
option domain-name-servers 10.252.1.1;
option domain-name "xingyao.com";
option routers 10.252.1.1;
option broadcast-address 10.252.1.255;
default-lease-time 600;
max-lease-time 7200;
}
-
- 给虚拟机新增一个网卡用作dhcp用,临时配置一个指定网段的IP
fconfig eno33554992 10.252.1.10/24
-
- 客户端主机新增一个同局域网的网卡,修改其网卡配置文件(拷贝自另一张网卡)
TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
NAME=eno33554992
UUID=77bf44b2-24b3-45ea-b4ce-7d9aafd78f50
DEVICE=eno33554992
ONBOOT=yes
#IPADDR=192.168.1.121
#PREFIX=24
#GATEWAY=192.168.1.1
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
-
- 重启网卡
Ifdown eno33554992
Ifup eno33554992
-
- 查看是否分配成功
Ifconfig
eno33554992: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.252.1.100 netmask 255.255.255.0 broadcast 10.252.1.255
- 绑定网卡(让某个IP固定分配给指定网卡)
修改server端dhcpd.conf
subnet 10.252.1.0 netmask 255.255.255.0 {
range 10.252.1.100 10.252.1.200;
option domain-name-servers 10.252.1.1;
option domain-name "xingyao.com";
option routers 10.252.1.1;
option broadcast-address 10.252.1.255;
default-lease-time 600;
max-lease-time 7200;
host Hadoop.HDPKFK02.com {
hardware ethernet 00:0c:29:c0:ad:e7;
fixed-address 10.252.1.150;
}
}
3.1 重启dhcp服务,重启客户端网卡,再查看客户端获得的IP
- 运行原理:client发送discover寻址报文,server接收到报文,响应客户端可以分配地址(offer),客户端请求地址(request),服务端分配地址(ack);如果ip地址租赁到期,则会再次向服务端请求(3次机会),若server在3次机会内响应了则给客户端续租,如果请求不成功,则系统自动分配一个169.250.0网段的地址。注意:多个dhcp服务器在同一个局域网中时,无法判断某个IP是否由其它server租赁出去了;dhcp无法跨局域网服务。