Linux Network Configuration with Netplan

Netplan describes network configuration in YAML and passes it to a renderer such as NetworkManager or systemd-networkd. The exact interface name and renderer vary by installation, so inspect them rather than copying a name from another machine.

Inspect the current state

ip link
ip address
ip route
resolvectl status

Back up the existing YAML before changing it:

sudo cp -a /etc/netplan /etc/netplan.backup

DHCP configuration

network:
  version: 2
  ethernets:
    enp1s0:
      dhcp4: true

Replace enp1s0 with the actual interface name. Apply interactively where possible:

sudo netplan try

netplan try rolls back if confirmation is not received. Use netplan apply only when you have console access or a recovery path.

Static IPv4 configuration

network:
  version: 2
  ethernets:
    enp1s0:
      addresses: [192.0.2.20/24]
      routes:
        - to: default
          via: 192.0.2.1
      nameservers:
        addresses: [192.0.2.53, 1.1.1.1]

The 192.0.2.0/24 network is documentation-only. Choose addresses from the network actually assigned to your lab. CIDR notation is explained in IPv4 Subnets, Netmasks, and CIDR.

Verify

ip address show dev enp1s0
ip route
ping -c 3 192.0.2.1
resolvectl query example.com

Do not confuse a working local route with working DNS. Test address reachability and name resolution separately.