Check your current (e.g., 21.321.01.00.158 ). Most flash failures happen when mixing basebands. If unsure, stick to the same major release number.

For most users, manual file downloads are unnecessary because the includes built-in update management tools. Routers Software & Firmware Download Huawei Routers Software & Firmware Download Huawei. Huawei B311-221 Firmware Release Notes | PDF - Scribd