I’ve written down the configuration method for setting up two AirMac Extreme units so I won’t forget.

AirMac Express: 10 units AirMac Extreme: 50 units

• Source: AirMac Expressの最大接続台数について | Apple サポートコミュニティ

Resetting AirMac Extreme to Factory Default State

1. Unplug the AirMac base station power.
2. Prepare a pen tip or toothpick (preferably something non-conductive and pointed) and press the reset button while connecting the AirMac base station power. Keep the reset button pressed during this time. Continue pressing the button until the LED lamp (status lamp) on the front of the unit blinks rapidly (for a few seconds).
3. When you release the button, the AirMac base station or Time Capsule will reset to factory default state.

• Source: AirMacベースステーションの工場出荷時状態にする方法

Set Google Public DNS for DNS server.

8.8.8.8 8.8.4.4

Reference Information

• Innovate!: 無線LANを無線LANで拡張(AirMac Extreme/Express)
• Wi-Fi base stations：Wi-Fi ベースステーションを追加することで、ワイヤレスネットワークの範囲を拡張する
• AirMacベースステーションを二台使ってWi-Fiの範囲を広げる | EzXNetwork
• システム管理者必見！ DHCPサーバのIPアドレスのリース期間設定の考え方 - TechNote
• iPhoneやMacのWi-Fi接続速度が遅い場合に見直したい項目 – OTTAN.XYZ

That’s all from the Gemba.