How to configure a static IP address on Linux

    Introduction

    By default, most servers obtain their IP address via DHCP. However, servers should use a static IP to ensure the address does not change after a reboot. This guide covers three methods depending on your Linux distribution.

    Method 1: Netplan (Ubuntu 18.04+)

    Ubuntu uses Netplan for network configuration. Configuration files are located in /etc/netplan/.

    Step 1: Identify your network interface

    ip link show

    Common names: eth0, ens18, enp0s3.

    Step 2: Edit the Netplan configuration

    sudo nano /etc/netplan/01-netcfg.yaml

    Replace the content with:

    network:
  version: 2
  renderer: networkd
  ethernets:
    ens18:
      addresses:
        - 203.0.113.10/24
      routes:
        - to: default
          via: 203.0.113.1
      nameservers:
        addresses:
          - 8.8.8.8
          - 1.1.1.1

    Replace ens18 with your interface name, and adjust the IP, gateway, and DNS values.

    Step 3: Apply the configuration

    sudo netplan apply

    Step 4: Verify

    ip addr show ens18
ip route show

    Method 2: /etc/network/interfaces (Debian)

    Debian uses the traditional interfaces file for network configuration.

    Step 1: Edit the interfaces file

    sudo nano /etc/network/interfaces

    Find the section for your interface (e.g., eth0) and change it from dhcp to static:

    auto eth0
iface eth0 inet static
    address 203.0.113.10
    netmask 255.255.255.0
    gateway 203.0.113.1
    dns-nameservers 8.8.8.8 1.1.1.1

    Step 2: Restart networking

    sudo systemctl restart networking

    Step 3: Verify

    ip addr show eth0
ip route show

    Method 3: NetworkManager (AlmaLinux / RHEL / Rocky Linux)

    RHEL-based distributions use NetworkManager and the nmcli command-line tool.

    Step 1: Identify the connection name

    nmcli connection show

    Output example:

    NAME                UUID                                  TYPE      DEVICE
System eth0         a1b2c3d4-e5f6-7890-abcd-ef1234567890  ethernet  eth0

    Note the connection name (e.g., System eth0 or ens18).

    Step 2: Set the static IP

    sudo nmcli connection modify "System eth0"   ipv4.addresses 203.0.113.10/24   ipv4.gateway 203.0.113.1   ipv4.dns "8.8.8.8 1.1.1.1"   ipv4.method manual

    Step 3: Restart the connection

    sudo nmcli connection down "System eth0"
sudo nmcli connection up "System eth0"

    Step 4: Verify

    nmcli connection show "System eth0" | grep ipv4
ip addr show eth0

    Alternative: Edit the connection file directly

    NetworkManager stores connection files in /etc/NetworkManager/system-connections/ (or /etc/sysconfig/network-scripts/ on older systems). You can edit these files and then reload:

    sudo nmcli connection reload
sudo nmcli connection up "System eth0"

    Configuring DNS separately

    If DNS is not set via the network configuration, you can edit /etc/resolv.conf directly:

    nameserver 8.8.8.8
nameserver 1.1.1.1

    Note: On systems using NetworkManager or systemd-resolved, this file may be overwritten. Use the methods above to set DNS persistently.

    Quick reference

    Distribution Config method Config file(s) Apply command
    Ubuntu 18.04+ Netplan /etc/netplan/*.yaml sudo netplan apply
    Debian interfaces /etc/network/interfaces sudo systemctl restart networking
    AlmaLinux / RHEL NetworkManager nmcli or /etc/NetworkManager/system-connections/ sudo nmcli connection up "name"
    Published