Enable Ethernet-WiFi Bridge

"Wireless Made Easy!" - This example application bridge the LAN and Wireless LAN on a single and same sub network

Devices: WFI32E01 | LAN8720

Watch the video and see how to enable L2 Bridging function with WFI32E Curiosity board

⚠ Disclaimer

THE SOFTWARE ARE PROVIDED "AS IS" AND GIVE A PATH FOR SELF-SUPPORT AND SELF-MAINTENANCE.

This repository contains unsupported example code intended to help accelerate client product development. It is not validated for production nor audited for security best-practices.

Note that while this repository is unsupported, Microchip welcome community contributions, and all pull-requests will be considered for inclusion into the repository.

Interact with peers in the community at WiFi Forum.

Description

From wikipedia, the network bridging is a function that creates a single, aggregate network from more than two communication networks.

Routing and bridging are often misinterpreted as the same function. Routing function allows more than two networks to communicate while remaining as separate/independent networks. Whereas, bridging function connects two separate networks as if they were a single network.

In the OSI model, bridging is performed in the data link layer (layer 2).

Bridging is independent of IP addresses. With one or more wireless segments in the bridged network, the device can be called a wireless bridge.

Below are the key points to consider while creating a bridging project:

• The bridge knows only MAC addresses and doesn't know anything else
• The bridge nver forwards a packet back to the interface the packet came from to avoid loops
• If the packet destination (MAC) address is multicast or broadcast, the packet will be forwarded on all the other interfaces
  • It will be passed internally to the stack running on top of the bridge too for internal processing
• If the packet destination is unicast:
  • If it is an address of one of the interfaces on the bridge host, the packet will be passed for internal processing
  • If it is the address of a host that the MAC bridge knows about, then the packet will be forwarded only on that interface
    • The bridge knows where various hosts are by looking at the source MAC address of the incoming packets
  • Otherwise it will be forwarded on all interfaces

L2 Bridging Implementation

PIC32MZW1/WFI32E set as an AP can be used as a Wireless Bridge connecting multiple wireless and wired networks to form a single network.

DHCP Server can be either in WFI32 device or outside. It is important that only one DCHPS exists in the setup.

The L2 bridging implementation is according to the IEEE 802.1D - 2004 standard document. It is recommended to read the standard to understand the purpose and implementation of the software module.

The command "bridge" has a help in it. It supports statistics, status or FDB entries. These commands are very basic and simple.

In the L2 bridging software implementation, a single task for the bridge operates, the one at the MAC level. The stack does not differentiate between Ethernet and Wi-Fi MACs, they are all the same. It does not matter how many MACs we bridge, the code is the same, just one bridge module dealing with all the virtual MACs for each interface.

Software requirement

The L2 bridging functionality can be enabled or disabled using MPLAB Harmony Configurator (MHC) with the NET repo (3.7.1 or above) and wireless_wifi repo (3.4.0 or above).

Checkout the following files from the Net repository (in the folder net/tcpip) for more information on the bridge implementaion:
tcpip_mac_bridge.c,
tcpip_mac_bridge_manager.h,
tcpip_mac_bridge_private.h,
tcpip_mac_bridge.h

The sample project has been created and tested with the following Software Development Tools:

• MPLAB X IDE v6.00
• MPLAB XC32 v3.01
• MPLAB Harmony v3.6.4
  • mhc v3.8.2
  • csp v3.10.0
  • core v3.10.0
  • wireless_wifi v3.6.1
  • dev_packs v3.10.0
  • wireless_system_pic32mzw1_wfi32e01 v3.6.1
  • wolfssl v4.7.0
  • net v3.7.4
  • crypto v3.7.5
  • CMSIS-FreeRTOS v10.3.1

Hardware setup using the WFI32 Curiosity Board

• Computer connected to WFI32 Curiositiy board over USB POWER (J204)
• J202 = VBUS
• J301 = open

USB-to-UART cable between the computer and GPIO Header UART1 pins (Rx, GND, Tx) to observe the console logs.

• PIC32 LAN8720 PHY Daughter Board AC3200043-3 plugged in WFI32 Cursiotiy Board thru J208

• An Ethernet cable between PHY Daughter board and the Home Router

MHC Configuration

• Open the project WiFi-ethernet dual interface located in <HarmonyFrameworkFolder>/wireless/apps/wifi_eth_dual_interface with MPLAB X IDE

• Open Harmony Configurator

• Under Project Graph > Root, set the AP parameters required for a station device to connect to the Bridge in WiFi Service

• Under Project Graph > APPLICATION LAYER:
  • Select DHCP Server
  • Untick DHCP Server Instance 0 box

DHCP Server can be either in WFI32 device or outside. It is important that only one DCHPS exists in the setup

• Under Project Graph > APPLICATION LAYER:
  • Select TCP/IP Application Layer Configuration
  • Add DHCP CLIENT and DNS CLIENT components
  • Remove DHCP Server

• Under Project Graph > System Configuration, make sure the Ethernet and the WiFi MAC instances are enabled in the NETCONFIG component

• Select the ETHMAC component, expand Ethernet Rx Filters Selection and check Accept Not Me Unicast Packets to enable the promiscuous mode

• Select the MAC Instance 0 from the NETCONFIG component
  • Make sure IPv4 Static Address = 0.0.0.0
  • Disable DHCP Flag, DNS Flag and Multicast under Network Configuration Start-up Flags
  • Enable Add Interface to MAC Bridge under Advanced Settings

• Select the MAC Instance 1 from the NETCONFIG component
  • Make sure IPv4 Static Address = 0.0.0.0
  • Enable DHCP Flag and DNS Flag under Network Configuration Start-up Flags
  • Enable Add Interface to MAC Bridge under Advanced Settings

• Select the NETCONFIG component and check Enable the MAC Bridge Commands

• Generate the code

With the above settings, the WFI32 is now ready to work as a Wi-Fi Network bridge

Try it

1. Build and program the code
   • located in /firmware folder with DCHP Server running on WFI32E
   • located in /firmware_wo_dhcp folder with DCHP Server running outside WFI32E
2. Plug the Ethernet cable from the PHY Daughter board to your own Home Router
3. Reset the WFI32E Curiosity board

4. Connect a station in Wireless to the WLAN network created by the WFI32 device in SoftAP mode

5. To evaluate performance, open iPerf server on a station connected to the Home router thru Ethernet cable

Get the IP address of the server > ipconfg

Run iperf server > iperf3 -s

6. On client side, open iPerf apps or execute > iperf3 -c <ipaddress of the server> command from a console

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