🛠 Configurer l'Ethernet 10/100 et piloter le Pi en SSH

Objectives

The Model B Rev 1 has neither WiFi nor Bluetooth: the 10/100 Ethernet port (SMSC LAN9512 chip) is the only network interface. You will configure a static IP, locate the board on the network, and work via SSH without a screen or keyboard. An architectural point to know: the LAN9512 chip combines a USB 2.0 hub and an Ethernet controller — the network passes through the single internal USB port, so heavy USB and Ethernet transfers share the same 480 Mbit/s link.

Hardware

• Raspberry Pi Model B Rev 1 + RJ45 Ethernet cable
• Box/router with a DHCP server
• A PC with an SSH client (Windows: built-in ssh or PuTTY)
• Stable 5 V micro-USB power supply (the F1 polyfuse protects the board; a poor-quality charger causes voltage drops and network crashes).

Complete code

# Cote du Pi : identifier l'interface (eth0 sur les images legacy)
ip addr show eth0

# IP dynamique par defaut (DHCP) : recuperer l'adresse
ip route get 1 | awk '{print $7; exit}'

# IP statique (Buster /etc/dhcpcd.conf, decommenter et adapter)
# interface eth0
# static ip_address=192.168.1.50/24
# static routers=192.168.1.1
# static domain_name_servers=192.168.1.1 8.8.8.8
sudo systemctl restart dhcpcd

# Autoriser le serveur SSH (raspi-config > Interface > SSH, ou :)
sudo systemctl enable --now ssh

# Cote du PC : connexion (utilisateur par defaut : pi)
ssh pi@192.168.1.50

Expected verification

ping 192.168.1.50 from the PC gets a response; ssh pi@192.168.1.50 opens a remote shell. ethtool eth0 (ethtool package) confirms the link "Speed: 100Mb/s". You are now controlling the Pi headless, without a monitor.

Common errors

• Looking for WiFi: wlan0 does not exist on this board, only eth0.
• Relying on the Ethernet light: the LED on the jack does not prove that a DHCP lease was obtained, check ip addr.
• Disappointing throughput (~10 MB/s max): normal, it is 100 Mbps behind a shared USB hub, not gigabit.
• ssh: connect to host ... refused: the SSH server is not enabled on the image.
• Powering via a USB hub: voltage drop, network disconnections, and polyfuse triggering.