DHCP service configuration and construction in Centos 7 system

DHCP service construction under Centos 7

• DHCP will not be introduced in detail. The function of DHCP can be configured with a router or switch (if supported), or it can be realized by building a server (Linux and windows). Now let’s talk about the configuration of DHCP service in CentOS 7 version. step

  Several parameters that the DHCP service needs to provide

  1), IP address and subnet mask;

  2), the default gateway;

  3), the lease time (if the time expires, the contract needs to be renewed, if the client does not renew the contract, the server will recycle the allocated IP address);

• 
  I will briefly talk about the three elements of service installation configuration startup mount and network card configuration

1. Mounting and network card configuration

1.1 mount

[root@localhost ~]# mkdir /media/cdrom
[root@localhost ~]# mv /etc/yum.repos.d/CentOS-Base.repo 1
[root@localhost ~]# vi /etc/yum.repos.d/CentOS-Media.repo 
[root@localhost ~]# mount /dev/cdrom /media/cdrom/

1.2 Network card configuration

[root@localhost ~]# vi /etc/sysconfig/network-scripts/ifcfg-ens33 

ONBOOT=yes
IPADDR=192.168.10.10
NETMASK=255.255.255.0
GATEWAY=192.168.10.2
DNS1=192.168.10.10

restart network card

[root@localhost ~]# systemctl restart network

2. Install DHCP service

2.1 Install DHCP service

yum install -y dhcp

Copy the file to the DHCP master file

cp -p /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example /etc/dhcp/dhcpd.conf 
cp：是否覆盖"/etc/dhcp/dhcpd.conf"？ yes

3. Configure the DHCP master file

3.1 Configuring the DHCP master file

• cd /etc/dhcp/dhcpd.conf

• Enter the configuration file and use shift+: Then enter set nu to view the line number and find line 47

• before fixing
  

• after modification

45 
     46 # A slightly different configuration for an internal subnet.
     47 subnet 192.168.10.0 netmask 255.255.255.0 {
    
    
     48   range 192.168.10.1 192.168.10.30;
     49   option domain-name-servers 192.168.10.10;
     50   option domain-name "dhcp";
     51   option routers 192.168.10.2;
     52   option broadcast-address 10.5.5.31;
     53   default-lease-time 600;
     54   max-lease-time 7200;
     55 }

4. Restart the DHCP service

4.1 Restart the DHCP service

[root@localhost ~]# systemctl restart dhcpd

5. Add a network adapter

5.1 Adding a network adapter

6. Result test

6.1 Result test

• Use ip a to view the IP address of the network card
  

• systemctl status dhcpd Check the status of the dhcp server.
  
  If active is displayed, it means that the DHCP service is successfully enabled and the setup is complete.