DHCP 架設設定 - c8

1. 安裝 dhcp 套件

   [root@msi ~]# dnf install dhcp-server
   

2. /etc/dhcp/dhcpd.conf 設定如下：。

   [root@msi ~]# vim /etc/dhcp/dhcpd.conf
   [root@msi ~]# cat /etc/dhcp/dhcpd.conf
   #
   # DHCP Server Configuration file.
   #   see /usr/share/doc/dhcp-server/dhcpd.conf.example
   #   see dhcpd.conf(5) man page
   #
   ddns-update-style none;
   option space PXE;
   
   subnet 192.168.1.0 netmask 255.255.255.0 {
   
   class "PXE" {
   	match if substring(option vendor-class-identifier, 0, 9) = "PXEClient";
   		option vendor-encapsulated-options 01:04:00:00:00:00:ff;
   		option boot-size 0x11;
   		filename "pxelinux.0";
   #		option tftp-server-name "deyu.wang";
   		option vendor-class-identifier "PXEClient";
   		vendor-option-space PXE;
   	}
   
   
   #	   The following lines are standard all of the time.
   		option routers 192.168.1.254;
   		option subnet-mask 255.255.255.0;
   		option domain-name "deyu.wang";
   		option domain-name-servers 192.168.1.254,8.8.8.8,168.95.1.1,139.175.10.20;
   		default-lease-time 21600;
   		max-lease-time 43200;
   
   		# Assign IPs 101-100 to PXE clients
   		pool {
   			allow members of "PXE";
   			default-lease-time 12;
   			max-lease-time 18;
   			range 192.168.1.250 192.168.1.253;
   		}
   		pool {
   			deny members of "PXE";
   			range 192.168.1.100 192.168.1.199;
   		}
   #   The following lines are examples of kickstart directives.
   	next-server 192.168.1.254;
   }
   

3. dhcp 的網卡，依照 /etc/sysconfig/dhcpd 有服務啟動的範例設定。

   [root@msi ~]# grep example -A5 /etc/sysconfig/dhcpd
   # example:
   # $ cp /usr/lib/systemd/system/dhcpd.service /etc/systemd/system/
   # $ vi /etc/systemd/system/dhcpd.service
   # $ ExecStart=/usr/sbin/dhcpd -f -cf /etc/dhcp/dhcpd.conf -user dhcpd -group dhcpd --no-pid <your_interface_name(s)>
   # $ systemctl --system daemon-reload
   # $ systemctl restart dhcpd.service
   

4. 依範例實作，dhcp.service 中的網卡還是用變數 DHCPDARGS，並在 /etc/sysconfig/dhcpd 中設定此變數。

   [root@msi ~]# cp /usr/lib/systemd/system/dhcpd.service /etc/systemd/system/
   [root@msi ~]# grep Exec /etc/systemd/system/dhcpd.service
   ExecStart=/usr/sbin/dhcpd -f -cf /etc/dhcp/dhcpd.conf -user dhcpd -group dhcpd --no-pid $DHCPDARGS
   [root@msi ~]# tail -1 /etc/sysconfig/dhcpd
   DHCPDARGS=wlo1
   

5. 啟動服務

   [root@msi ~]# systemctl --system daemon-reload
   [root@msi ~]# systemctl restart dhcpd.service
   

6. 查看服務狀態 active

   [root@msi ~]# systemctl status dhcpd.service
   ● dhcpd.service - DHCPv4 Server Daemon
      Loaded: loaded (/etc/systemd/system/dhcpd.service; disabled; vendor preset: disabled)
      Active: active (running) since Thu 2021-07-15 07:11:44 CST; 1min 1s ago
        Docs: man:dhcpd(8)
              man:dhcpd.conf(5)
    Main PID: 4587 (dhcpd)
      Status: "Dispatching packets..."
       Tasks: 1 (limit: 48313)
      Memory: 4.9M
      CGroup: /system.slice/dhcpd.service
              └─4587 /usr/sbin/dhcpd -f -cf /etc/dhcp/dhcpd.conf -user dhcpd -group dhcpd --no-pid wlo1