You absolutely don’t have to manually add every host entry directly in dhcpd.conf. ISC DHCPD supports using an include directive to pull in external files that contain your static host configurations—this lets you keep all your MAC, IP, and hostname mappings in a single dedicated file, keeping your main config clean and far easier to manage.

Here’s how to set it up step by step: #

1. Create a dedicated file for static host mappings
   Make a new file (e.g., /etc/dhcp/static_hosts.conf) and define each host with its MAC address, fixed IP, and hostname. Each entry follows the standard DHCP host block syntax:

   host office_printer {
     hardware ethernet 00:11:22:33:44:55;
     fixed-address 192.168.0.20;
     option host-name "office_printer";
   }
   
   host johns_desktop {
     hardware ethernet AA:BB:CC:DD:EE:FF;
     fixed-address 192.168.0.30;
     option host-name "johns_desktop";
   }
   

2. Include this file in your main dhcpd.conf
   Open your primary DHCP config file (usually /etc/dhcp/dhcpd.conf) and add an include line pointing to your static hosts file. Place it after your subnet declarations (where host definitions are logically grouped):

   # Example main dhcpd.conf snippet
   subnet 192.168.0.0 netmask 255.255.255.0 {
     range 192.168.0.100 192.168.0.200;
     option routers 192.168.0.1;
     option domain-name "local";
   }
   
   # Pull in our static host mappings
   include "/etc/dhcp/static_hosts.conf";
   

3. Restart DHCPD to apply changes
   After editing either file, restart the DHCP service to load the updated configuration. On most systemd-based distros, run:

   sudo systemctl restart isc-dhcp-server
   

Important tips: #

• The included file is parsed exactly as if its content was directly in dhcpd.conf, so you can use all the same syntax and options you would in the main config.
• For larger networks, you can even split static hosts into multiple files (e.g., one per department) and include them all separately—this scales much better than cramming everything into dhcpd.conf.
• Make sure the included file has correct permissions (readable by the DHCP daemon user, usually dhcpd or root) to avoid parsing errors.

This approach is a widely recommended best practice for managing static DHCP assignments, as it separates dynamic pool configuration from static mappings and makes it simpler to update or audit host entries without disrupting the main config.

内容的提问来源于stack exchange，提问作者excessive