iOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPhone 6+, released on 2017-12-13T18:12:36Z. The update package is 1.24 GB. This is a delta (partial) update that requires 10.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ee4da1d5d64e618aaff2349f210f744411ff6963.zip.