Configuring DHCP

Introduction

Dynamic Host Configuration Protocol (DHCP) is a network management protocol used to dynamically assign IP addresses to devices on a network. This tutorial will guide you through the process of configuring a DHCP server on a Linux system.

Prerequisites

Before you start, ensure you have the following:

• A Linux system with root or sudo access.
• Basic understanding of network concepts.

Step 1: Install DHCP Server

First, you need to install the DHCP server package. On most Linux distributions, this can be done using the package manager.

On CentOS or RHEL, use the following commands:

Step 2: Configure DHCP Server

The main configuration file for the DHCP server is /etc/dhcp/dhcpd.conf. Open this file in your preferred text editor:

Add the following configuration to define a subnet and IP address range:

subnet 192.168.1.0 netmask 255.255.255.0 {
    range 192.168.1.10 192.168.1.100;
    option routers 192.168.1.1;
    option subnet-mask 255.255.255.0;
    option domain-name-servers 8.8.8.8, 8.8.4.4;
    option domain-name "example.com";
}
                

This configuration defines a subnet 192.168.1.0/24 and assigns IP addresses from 192.168.1.10 to 192.168.1.100. Adjust these values according to your network configuration.

Step 3: Assign Static IP Addresses

To assign a static IP address to a specific device, add a host declaration within the subnet block:

host mydevice {
    hardware ethernet 00:11:22:33:44:55;
    fixed-address 192.168.1.50;
}
                

Step 4: Start the DHCP Server

After configuring the DHCP server, start the service:

On CentOS or RHEL:

Step 5: Verify DHCP Server

To verify that the DHCP server is running correctly, check its status:

You can also check the DHCP leases file to see the assigned IP addresses:

Conclusion

You have successfully configured a DHCP server on your Linux system. DHCP simplifies network management by automatically assigning IP addresses to devices, making it an essential tool for network administrators.