【DHCP Server】ubuntu18.4安装DHCP server服务
参考连接：Ubuntu LTS 18.04 配置DHCP Server
1.安装dhcp服务
root@liuting:~# apt install isc-dhcp-server
2.修改网卡配置
root@liuting:~# vim /etc/netplan/50-cloud-init.yaml
network:
ethernets:
ens160:
addresses:
- 172.20.80.183/16
gateway4: 172.20.0.1
nameservers:
addresses:
- 8.8.8.8
ens192:
dhcp4: false
addresses:
- 22.22.22.1/24
version: 2root@liuting:~# netplan apply
3.修改 /etc/default/isc-dhcp-serve
root@liuting:~# vim /etc/default/isc-dhcp-server
修改如下值：
INTERFACESv4="ens192"4.配置DHCP Server
root@liuting:~# vim /etc/dhcp/dhcpd.conf
配置域名和域名服务器：
option domain-name "www.baidu.com";
option domain-name-servers 8.8.8.8,114.114.114.114;
# 配置租期：
default-lease-time 6000;
max-lease-time 7200;
# 取消如下注释：
authoritative;
# 配置子网配置，可直接粘贴到文档末尾：
subnet 22.22.22.0 netmask 255.255.255.0 {
range 22.22.22.100 22.22.22.200;
option routers 22.22.22.1;
option subnet-mask 255.255.255.0;
}5.重启服务
root@liuting:~# systemctl enable isc-dhcp-server #开机自启动
root@liuting:~# systemctl restart isc-dhcp-server # 重启服务
查看服务进程是否启动：
root@liuting:~# netstat -aunp | grep dhcpd
udp 0 0 0.0.0.0:63202 0.0.0.0:* 11509/dhcpd
udp 0 0 0.0.0.0:67 0.0.0.0:* 11509/dhcpd
udp6 0 0 :::30033 :::* 11509/dhcpd
6.验证
拓扑：DHCP Server（Linux虚拟机网卡ens192）-----直连-------DHCP Client（交换机48口）
交换机直连接口配置：
interface eth-0-48
no switchport
ip address dhcp
在虚拟机抓包查看dhcp报文：
root@liuting:~# tcpdump -nei ens192
08:38:38.610235 66:66:66:66:66:66 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 356: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 66:66:66:66:66:66, length 314
08:38:38.610733 00:50:56:b2:0e:c8 > 66:66:66:66:66:66, ethertype IPv4 (0x0800), length 62: 22.22.22.1 > 22.22.22.100: ICMP echo request, id 41823, seq 0, length 28
08:38:39.612730 00:50:56:b2:0e:c8 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: 22.22.22.1.67 > 255.255.255.255.68: BOOTP/DHCP, Reply, length 300
08:38:39.613618 66:66:66:66:66:66 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 368: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 66:66:66:66:66:66, length 326
08:38:39.620899 00:50:56:b2:0e:c8 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: 22.22.22.1.67 > 255.255.255.255.68: BOOTP/DHCP, Reply, length 300
08:38:39.644349 66:66:66:66:66:66 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 60: Request who-has 22.22.22.100 (ff:ff:ff:ff:ff:ff) tell 22.22.22.100, length 46
08:38:39.644391 66:66:66:66:66:66 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 60: Request who-has 22.22.22.1 tell 22.22.22.100, length 46
08:38:39.644403 00:50:56:b2:0e:c8 > 66:66:66:66:66:66, ethertype ARP (0x0806), length 42: Reply 22.22.22.1 is-at 00:50:56:b2:0e:c8, length 28
08:38:43.645098 00:50:56:b2:0e:c8 > 66:66:66:66:66:66, ethertype ARP (0x0806), length 42: Request who-has 22.22.22.100 tell 22.22.22.1, length 28
08:38:43.645769 66:66:66:66:66:66 > 00:50:56:b2:0e:c8, ethertype ARP (0x0806), length 60: Reply 22.22.22.100 is-at 66:66:66:66:66:66, length 46
在虚拟机查看已经分配的地址：
root@liuting:~# dhcp-lease-list
Reading leases from /var/lib/dhcp/dhcpd.leases
MAC IP hostname valid until manufacturer
============================================================================================
66:66:66:66:66:66 22.22.22.100 ting13 2020-07-16 08:58:39 -NA-
交换机上查看分配到的地址：
switch# show dhcp client verbose
DHCP client informations:
============================================================
eth-0-48 DHCP client information:
Current state: BOUND
Allocated IP: 22.22.22.100 255.255.255.0
Lease/renewal/rebinding: 1188/461/1038 seconds
Lease from 2020-07-16 08:55:43 to 2020-07-16 09:15:43
Will Renewal in 0 days 0 hours 7 minutes 41 seconds
DHCP server: 22.22.22.1
Transaction ID: 0x58953f43
Default router: 22.22.22.1
Client ID: switch-6666.6666.6666-eth-0-48