Raspberry Pi 4: Wi Fi Hotspot Bridged To Ethernet Network

Prerequisites

• A Raspberry Pi 4 with an operating system installed (e.g., Raspberry Pi OS).
• Ethernet cable connected to a network.
• Access to the Raspberry Pi’s GUI or terminal.

Step 1: Set Up the Hotspot

1. Open the Network Manager GUI:

   • In the taskbar, click on the network icon.
   • Open Network Connections.

2. Create a Wi-Fi Hotspot:

   • Click Add, select Wi-Fi, and click Create.
   • Configure the hotspot:
     • SSID: Enter a name for the hotspot (e.g., RPI-Hotspot).
     • Mode: Select Hotspot.
     • Security: Set to WPA2 Personal and provide a password.

3. Save the Configuration:

   • Save the hotspot connection.

Step 2: Enable IPv4 Sharing

1. Edit the Hotspot Connection:

   • In the Network Connections window, select the hotspot and click Edit.
   • Go to the IPv4 Settings tab.

2. Set IPv4 Method:

   • Change the method to Shared to other computers.
   • Save the configuration.

3. Restart the Hotspot:

   • Restart the connection to apply changes.

Step 3: Enable NAT (Optional, if Needed)

To ensure traffic is routed correctly, set up Network Address Translation (NAT):

1. Enable IP Forwarding:

   • Run the following command to enable IP forwarding:
     bash

      

     echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward
     
     
   • Make the change persistent by adding it to /etc/sysctl.conf:
     plaintext

     net.ipv4.ip_forward=1

2. Set Up NAT with iptables:

   • Add a NAT rule for forwarding traffic from Wi-Fi to Ethernet:
     bash
     
     

     sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
     
     
   • Save the iptables configuration:
     bash
     
     

     sudo mkdir -p /etc/iptables sudo iptables-save > /etc/iptables/rules.v4
     
     
   • Install iptables-persistent to restore rules on boot:
     bash
     
     

     sudo apt install iptables-persistent sudo systemctl enable netfilter-persistent


Step 4: Connect Devices to the Hotspot

1. Connect a Device:

   • Use your phone, laptop, or other Wi-Fi-enabled device to connect to the hotspot.
   • Enter the password you configured in Step 1.

2. Verify Connectivity:

   • Check that the device gets an IP address from the Raspberry Pi.
   • Test connectivity to devices on the Ethernet network by pinging their IP addresses or accessing services (e.g., SSH).