Instructions for setting up WiFi and connecting to AltWFC network - retr0s4ge/desmume GitHub Wiki

1- Search for, download the firmware files below (md5sum must match) and place them in "firmware" subdirectory

Required Firmware Files:

Filename	Description	md5sum
firmware.bin	NDS Firmware - Required	145eaef5bd3037cbc247c213bb3da1b3
bios7.bin	ARM7 BIOS - Required	df692a80a5b1bc90728bc3dfc76cd948
bios9.bin	ARM9 BIOS - Required	a392174eb3e572fed6447e956bde4b25

2- Download Winpcap software from https://www.winpcap.org/install/default.htm and install it

3- Start desmume and open the Emulation Settings (Config>Emulation Settings), then

1- Set the check boxes for the following:
  Use external BIOS images, Use external firmware image, Load User Settings from file

2- Browse for and select the ARM9 BIOS image, ARM7 BIOS image, Firmware image then click OK

4- Open the WiFi Settings (Config>Wifi), then

1- Under Wifi mode: Select the radio button for "Infrastructure"

2- Under Infrastructure settings:
  Select the Ethernet adapter you are currently using for connecting to the internet then click OK.
  Note that settings for infrastructure mode will be grayed out if Winpcap is not installed correctly.

5- Setup connection to the AltWFC network by following the instructions below

This needs to be done ONCE per emulator!

WfcPatcher https://github.com/AdmiralCurtiss/WfcPatcher/releases

AltWFC Server List https://github.com/polaris-/dwc_network_server_emulator/wiki/List-of-Servers

5a- Download the most recent version of WfcPatcher

5b- Drag and drop the ROM file(s) onto WfcPatcher.exe.
    Note: WfcPatcher works correctly with most ROMs, but some need special patching instructions

5c- The output (patched) ROM file has (NoSSL) at the end of its filename. 

5d- Open the patched ROM in desmume, then go to Nintendo WFC Settings (Inside the game)

5e- Select Options, then Erase Nintendo WFC Configuration. The ROM will be closed.

5f- Open the ROM again in desmume,  then go to Nintendo WFC Settings (Inside the game)

5g- Select Nintendo Wi-Fi Connection Settings, then Connection 1, then Search for an Access Point

5h- SoftAP access point should appear, select OK. A connection test will be performed but WILL FAIL.

5i- Select Connection 1 again, and scroll down to the bottom of the settings list

5j- Set Auto-obtain DNS to No

5k- Set the primary and secondary DNS servers to 104.131.93.87 (default AltWFC)
    If you want, you can choose any server from the AltWFC server list linked above

5l- Select Save Settings

5m- Reset the ROM and start a new game or load your in-game save

5n- start an activity requiring connection to WFC network

5o- The game will tell you that card and console information don't match.
    It will ask you if new information should be generated, accept this.

5p- After saving the new information, the game will attempt to connect to WFC network but WILL FAIL again.
    Don't try to connect again.

5q- Make an in-game save and then Reset the ROM

5r- Load the previous in-game save and start the activity requiring connection to WFC network

5s- You should finally be able to connect successfully to AltWFC network !

Notes:

1- The resulting settings (including WFC ID) are saved in firmware.dfc file inside the Battery folder.

2- If you need to run multiple copies of an online game at the same time as 2 different players then make sure to follow the instructions above for 2 separate copies of the emulator, so that you get a 2 different firmware.dfc files (i.e different WFC ID for each copy)