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HOWTO-configure-network-on-ubuntu

· 2 min read

Set netplan configuration​

Set Dynamic IP address​

for inter in $(ls /sys/class/net); do
if [[ $inter != 'lo' ]]; then
cat << EOF > /etc/netplan/99-$inter.yaml
network:
  ethernets:
    $inter:
      dhcp4: true
  version: 2
  renderer: networkd
EOF
ip link set dev $inter up
fi
done

Set Static IP address​

network:
  version: 2
  renderer: networkd
  ethernets:
    eth0:                      # Replace with your interface name
      dhcp4: false             # Disable DHCP for IPv4
      addresses:
        - 192.168.1.100/24     # Static IP address with subnet mask
      routes:
        - to: 0.0.0.0/0        # Default route (default gateway)
          via: 192.168.1.1     # Replace with your gateway IP
      nameservers:
        addresses:
          - 8.8.8.8            # Primary DNS server (Google DNS)
          - 8.8.4.4            # Secondary DNS server

Apply configurations​

netplan apply

Check IP status​

ip a

Set network config on boot​

  1. combine script as a shell /etc/netplan/gen_netplan_config.sh

    #!/bin/env bash

    umask 377

    for inter in $(ls /sys/class/net); do
    if [[ $inter != 'lo' ]] && [[ ! -e /etc/netplan/99-$inter.yaml ]]; then
    cat << EOF > /etc/netplan/99-$inter.yaml
    network:
      ethernets:
        $inter:
          dhcp4: true
      version: 2
      renderer: networkd
    EOF
    ip link set dev $inter up
    fi
    done
    netplan apply

  2. write /usr/lib/systemd/system/wait-netplan-dhcp.service[^3]

    [Unit]
    Description=Generate DHCP networking DHCP demo for netplan
    Before=network-online.target

    [Service]
    ExecStart=/etc/netplan/gen_netplan_config.sh

    [Install]
    WantedBy=multi-user.target

  3. start and enable

    systemctl start wait-netplan-dhcp
    systemctl enable wait-netplan-dhcp

Reference​