A: Check every 6 months. This device is mature (released ~2017), so major updates are rare. However, security patches still appear every 12–18 months.
To know if you need an update, you must check your current firmware. Do not rely on "I bought it last year." update+software+in+zte+mf297d
BD_MF297DV1.0.0B05).Pro Tip: If your firmware version ends in B01 or B02, you are significantly outdated. A: Check every 6 months
You will download the firmware via PC. Use a wired Ethernet connection between your PC and the ZTE MF297D (via USB tethering or a USB-to-Ethernet adapter). Wi-Fi updating is risky because a signal drop mid-update crashes the device. Navigate to Settings > Device Information > Firmware
This is the most dangerous step. Never download firmware from a random torrent or file-sharing site. Your ZTE MF297D is likely "branded" (customized) by your mobile carrier. Generic ZTE firmware will not work.