Wiimmfi

Wiimmfi is a replacement server for the now defunct Nintendo Wi-Fi Connection. It was created in 2014, by Wiimm and Leseratte.

Emulation Information
Make sure you are using an up-to-date version of Dolphin if you run into any issues. Dolphin definitely is too old, and earlier development versions might be as well. Wiimm and Leseratte are regularly adding features to Wiimmfi that might only have been added in recent versions of Dolphin, so if you run into trouble please update to the most recent development version.

NAND Backup
You need to use a NAND backup from a real Wii or Wii U console set up in Dolphin to be able to use Wiimmfi.

Read the configuration section below and configure the proper settings, then see the NAND Usage Guide on how to acquire and import a NAND backup. Make sure you use the automatic import (Tools → Import BootMii NAND Backup), the manual way (extracting the NAND and copying the files around) will not work.

Patch Needed
Before using Wiimmfi, games need to be patched via Wiimmfi Patcher. Just grab an ISO or WBFS file of the game you want to play, put it in the folder with the Wiimmfi Patcher, and run it. The patcher will then create a Wiimmfi-patched copy of each game you put into the folder.

Configuration
It is recommended to enable the "Allow Mismatched Region Settings" under Settings → General → Basic settings before importing your NAND backup, and keep that setting enabled permanently. If you boot an out-of-region game (a game that isn't from the same region as your NAND) without that setting enabled, it might generate a new console identity and restart your 7-day waiting period on Wiimmfi.

Note that if you're playing a Wiimmfi-patched copy of Mario Kart Wii, you must not increase the MEM1 size to beyond 32 MB. Increasing the MEM2 size to the maximum (128 MB) works just fine (and may help with larger mods / Custom Tracks), but increasing MEM1 to values higher than 32 MB can cause a Wiimmfi-patched MKWii copy to either crash on boot or while connecting to Wiimmfi.