In the world of 4G LTE routers, the ZLT P21 (often branded under carriers or sold as an OEM unit) is a workhorse device known for its compact design and reliable performance. However, like many cellular devices, it can fall victim to a common but critical issue: a corrupted or null IMEI (International Mobile Equipment Identity).
Most "repair files" found online contain a generic QCN. If you flash repair imei zlt p21.7z
Disclaimer: The following steps are for educational and restoration purposes only. Modifying IMEI data is regulated in many jurisdictions. Always ensure you are restoring the device's original IMEI. In the world of 4G LTE routers, the