Network Configuration on Raspberry Pi OS

Raspberry Pi Network Commands

Basic Network Information

• ip addr — Displays IP addresses, MAC addresses, and network interface status.
• route or ip route — Shows the paths packets take to reach network destinations.
• cat /etc/resolv.conf — Lists the DNS servers your Pi is using.
• hostname — Shows the current hostname.
• hostname -I — Displays the Pi’s IP address(es).

Network Connectivity Testing

• ping 8.8.8.8 — Checks if the internet or a specific IP is reachable.
• traceroute google.com — Shows the path data packets take to reach a host.
• nc -zv IP PORT — Checks if a port is open on a device.

Wi-Fi Management

• sudo iwlist wlan0 scan — Lists available Wi-Fi networks.
• Connect to Wi-Fi from CLI: Edit /etc/wpa_supplicant/wpa_supplicant.conf and add:

network={
  ssid="YourSSID"
  psk="YourPassword"
}
  

• Restart Wi-Fi: sudo wpa_cli -i wlan0 reconfigure
• iwconfig — Shows wireless network interface details, signal strength, and channel.

IP Configuration

• sudo dhclient -r wlan0 and sudo dhclient wlan0 — Releases and renews DHCP lease.
• Set static IP (example for eth0): Edit /etc/dhcpcd.conf:

interface eth0
static ip_address=192.168.1.10/24
static routers=192.168.1.1
static domain_name_servers=192.168.1.1 8.8.8.8
  

• sudo ip link set dev eth0 mtu 9000 — Useful for high-speed networks; check compatibility.

Monitoring & Troubleshooting

• ifstat, vnstat, or nload — Real-time bandwidth usage per interface.
• netstat -tuln — Lists listening TCP/UDP ports.
• ss -tuln — Modern replacement for netstat.
• iperf3 -s (server) / iperf3 -c SERVER_IP (client) — Test network speed.
• arp -a — Shows mapped IP addresses and MAC addresses in local network.

SSH & Remote Access

• sudo systemctl enable ssh and sudo systemctl start ssh — Enable SSH.
• ssh pi@192.168.1.20 — Connects to another device on the network.
• scp localfile pi@192.168.1.20:/home/pi/ — Secure file copy via SSH.

Network Debugging

• ip route get 8.8.8.8 — Display routing for specific host.
• ifconfig wlan0 or cat /sys/class/net/wlan0/statistics/rx_errors — Check interface statistics/errors.
• ping -M do -s 8972 192.168.1.1 — Useful for MTU testing.
• Advanced tools: tcpdump, wireshark, or nmap — For deeper network analysis.