On Tue, 3 Dec 2024 21:47:57 +0100 Andrew Lunn wrote: > Are you saying the OTP or NVMEM has a locally administered MAC address > stored in it? Is there a mechanism to change it? The point about > locally administered MAC addresses is that they are locally > administered. You may also enjoy reading this :) commit bfe9b9d2df669a57a95d641ed46eb018e204c6ce Author: Kristian Evensen <kristian.evensen@xxxxxxxxx> Date: Thu Jul 21 11:10:06 2016 +0200 cdc_ether: Improve ZTE MF823/831/910 handling The firmware in several ZTE devices (at least the MF823/831/910 modems/mifis) use OS fingerprinting to determine which type of device to export. In addition, these devices export a REST API which can be used to control the type of device. So far, on Linux, the devices have been seen as RNDIS or CDC Ether. When CDC Ether is used, devices of the same type are, as with RNDIS, exported with the same, bogus random MAC address. In addition, the devices (at least on all firmware revisions I have found) use the bogus MAC when sending traffic routed from external networks. And as a final feature, the devices sometimes export the link state incorrectly. There are also references online to several other ZTE devices displaying this behavior, with several different PIDs and MAC addresses.