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Networking

Updated Mar 27, 2021 ·

Tasks​

  1. Set your server to a fixed IP address that matches your current network configuration.
  2. Also set a second IP address 10.0.0.10/24 on the same network interface.
  3. Reboot and verify your network is still working with the new settings.

Solution​

1. Set a fixed IP address​

Set your server to a fixed IP address that matches your current network configuration. Look for the interface that is currently in use, typically something like eth0 or enp0s3.

ip a

Edit the /etc/netplan/ configuration file:

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

Edit the file to match your current network configuration. Replace INTERFACE_NAME with your actual network interface name and CURRENT_IP, GATEWAY, and DNS_SERVERS with your current settings.

network:
  version: 2
  renderer: networkd
  ethernets:
    INTERFACE_NAME:
      dhcp4: no
      addresses:
        - CURRENT_IP/24
      gateway4: GATEWAY
      nameservers:
        addresses:
          - DNS_SERVERS

2. Set the second IP Address​

Also set a second IP address 10.0.0.10/24 on the same network interface. In the same netplan configuration file, add another address line for the secondary IP:

network:
  version: 2
  renderer: networkd
  ethernets:
    INTERFACE_NAME:
      dhcp4: no
      addresses:
        - CURRENT_IP/24
        - 10.0.0.10/24
      gateway4: GATEWAY
      nameservers:
        addresses:
          - DNS_SERVERS

3. Reboot and verify​

Reboot and verify your network is still working with the new settings.

sudo netplan apply
sudo reboot

After the server reboots, check that both IP addresses are configured:

ip a

Check that the network is functioning correctly by pinging an external address and both configured IPs.

ping -c 4 8.8.8.8
ping -c 4 CURRENT_IP
ping -c 4 10.0.0.10