How to Configure a DHCP or Static IP on Ubuntu Server

Configuring network settings on Ubuntu Server is a crucial step in setting up a reliable and stable system. Whether you need a dynamically assigned IP address via DHCP or a fixed static IP, Ubuntu provides simple ways to configure your network settings.

Configuring a DHCP IP Address

By default, Ubuntu Server typically obtains an IP address via DHCP. If you need to ensure your server continues to use DHCP, follow these steps:

1. Open the Netplan configuration file:
   

   sudo nano /etc/netplan/00-installer-config.yaml
   

2. Ensure the following configuration is set:
   

   network:
     ethernets:
       eth0:
         dhcp4: true
     version: 2
   

   Replace eth0 with your actual network interface name if different.

3. Apply the changes:

   sudo netplan apply
   

Configuring a Static IP Address

If your server requires a fixed IP address, configure it manually:

1. Open the Netplan configuration file:

   sudo nano /etc/netplan/00-installer-config.yaml
   

2. Modify it to include your static IP configuration:
   

   network:
     ethernets:
       eth0:
         dhcp4: false
         addresses:
           - 192.168.1.100/24
         gateway4: 192.168.1.1
         nameservers:
           addresses:
             - 8.8.8.8
             - 8.8.4.4
     version: 2
   

   Adjust the IP address, gateway, and DNS servers as needed.

3. Save the file and apply the changes:

   sudo netplan apply
   

Verifying Network Configuration

To check if your changes were applied correctly, use:

ip a

Or to check your default gateway:

ip route

Conclusion

Setting up a DHCP or static IP on Ubuntu Server is straightforward with Netplan. Whether you prefer automatic configuration via DHCP or require a fixed address, these steps ensure a stable network connection.