eth1 - LAN Interface (USB Dongle)

Overview

The eth1 interface provides trusted wired LAN connectivity via a USB 3.0 Wired LAN adapter. This is an optional hardware component that expands Pimeleon router's wired connectivity for trusted devices that require reliable, high-speed network access.

Hardware Selection: We use a Realtek RTL8153 adapter because it has excellent kernel driver support (r8152 module) and performs reliably. When choosing USB network adapters, always verify Linux kernel compatibility first - it's wise to think ahead about driver support before purchasing hardware.

Hardware Details

• Type: USB 3.0 Wired LAN adapter
• Connection: USB port on Raspberry Pi 3B+
• Speed: 1000 Mbps (Gigabit)
• Driver: r8152 (kernel module)
• MAC Address: 00:e0:4c:68:04:98

Network Configuration

• Type: LAN (Local Area Network) - Trusted Wired
• IP Address: 192.168.76.1/24
• Network: 192.168.76.0/24 (Trusted LAN subnet)
• Broadcast: 192.168.76.255
• Status: Static IP assignment
• DHCP Range: 192.168.76.100-200 (served by Pimeleon device)

Device Classification

• Security Zone: Trusted
• Device Types: Workstations, servers, printers, NAS devices
• Access Level: Full internet access + local services
• Filtering: Minimal (trusted device policies)

Monitoring Commands

# Interface status
ip addr show eth1

# Link speed verification
cat /sys/class/net/eth1/speed

# Driver information
dmesg | grep r8152

# USB device information
lsusb | grep -i realtek

# Interface statistics
ip -s link show eth1

# Connected devices (DHCP leases)
cat /var/lib/dhcp/dhcpd.leases | grep 192.168.76

Driver Information

# Driver version and status
dmesg | grep "r8152.*eth1"
# Example output:
# r8152 1-1.1.3:1.0 eth1: v1.12.13
# r8152 1-1.1.3:1.0 eth1: carrier on

Troubleshooting

Interface Not Detected

1. Check USB connection: Ensure adapter is firmly plugged in
2. Verify USB detection: lsusb | grep -i realtek
3. Check driver loading: dmesg | grep r8152
4. Restart USB subsystem: Unplug/replug adapter
5. Check kernel modules: lsmod | grep r8152

No Network Connectivity

1. Check link status: ip link show eth1 (should show LOWER_UP)
2. Verify IP configuration: ip addr show eth1
3. Test cable connection: Try different ethernet cable
4. Check DHCP service: Ensure DHCP server is running for 192.168.76.0/24
5. Restart interface: sudo ip link set eth1 down && sudo ip link set eth1 up

Performance Issues

1. Verify gigabit speed: cat /sys/class/net/eth1/speed (should show 1000)
2. Check for USB 3.0: Ensure plugged into USB 3.0 port if available
3. Monitor USB bandwidth: Check if other USB devices are saturating bus
4. Cable quality: Use CAT5e or CAT6 ethernet cable

Hardware Requirements

• Optional Component: Pimeleon router functions without eth1
• USB Port: Requires one available USB port on Pimeleon device
• Power: Adapter draws power from USB (typically <2W)
• Cable: Standard ethernet cable (CAT5e/CAT6 recommended)

Use Cases

• Trusted Workstations: Desktop computers requiring reliable connectivity
• Server Connections: Local servers, NAS, print servers
• Gaming Devices: Consoles requiring low-latency connections
• IoT Devices: Trusted smart home devices
• Backup Connectivity: Secondary wired connection for Wi-Fi devices

Related Documentation:

• Network Topology - Overall network architecture
• IP Allocation - Network addressing and DHCP configuration
• eth0 - WAN Interface - WAN interface configuration
• wlan0 - WiFi Interface - Wireless interface configuration

← Network Topology | ← Network Interfaces