🛠 Configurer l'Ethernet Gigabit et se connecter en SSH

Objectives

Set up the ODROID-N2 headless (without a screen): configure Gigabit Ethernet (Amlogic dwmac controller + Realtek RTL8211F PHY, measured at over 900 Mbit/s Tx/Rx by CNX) and control the board via SSH. Important: the board has NO built-in WiFi/BT — an Ethernet cable is mandatory, or you need a USB adapter.

Hardware

• ODROID-N2/N2+ with an Armbian image on microSD
• RJ45 Ethernet cable to the box/router
• DC 5.5×2.1 mm power supply: 7.5–18 V (up to 25 W on N2; 7.5–16 V ≤ 2 A on N2+, 12 V/2 A kit)
• A PC with an SSH client

Complete code

# --- Sur la carte (première connexion via écran clavier ou série) ---
sudo nmtui          # ou éditer /etc/network/interfaces
# DHCP simple avec systemd-networkd :
cat <<'EOF' | sudo tee /etc/systemd/network/20-eth0.network
[Match]
Name=end0 eth0*
[Network]
DHCP=yes
EOF
sudo systemctl restart systemd-networkd
ip -4 addr show | grep inet          # noter l'IP, p. ex. 192.168.1.42
sudo systemctl enable --now ssh

# --- Depuis le PC ---
ssh odroid@192.168.1.42             # mot de passe par défaut de l'image
# Débit vérifié attendu (>900 Mbit/s) :
iperf3 -s                            # sur la carte
iperf3 -c 192.168.1.42               # sur le PC serveur iperf3 du LAN

Expected verification

ip -4 addr show displays a DHCP address on the Ethernet interface (commonly named end0/eth0 on meson-g12b). ethtool end0 | grep -i speed indicates 1000Mb/s. The SSH session opens on the first attempt; iperf3 approaches 940 Mbit/s. ping works from the gateway.

Common errors

• Expecting WiFi: the wireless chip is absent from the board; use a USB dongle or stay wired.
• Ethernet LED off: cable or 100 Mbit/s port; the RTL8211F PHY does not negotiate at 1 Gbit — try another cable (Cat 5e minimum).
• Wrong interface in the networkd file: list interfaces with ip link (names vary: end0, eth0, enx…).
• Insufficient power supply: undervoltage causing USB/Ethernet disconnections; use the provided 12 V/2 A charger.
• ssh: connection refused: the ssh service is not running (systemctl status ssh) or the firewall is blocking it.
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