Carat1 wrote

Why do you want to change it? I am not sure if we are allowed to do this.

That's a good question. But as for an alleged ban to change the MAC address: this is nonsense, sorry. It absolutely could make sense to be able to change the MAC address of the WAN interface (and in some cases for the LAN interface, too) for very good reasons.

For example one of such reasons is given by certain ISPs (e.g. in Austria), which use the MAC address of a device to authorize for Internet access, which means that you can't just replace their router by the one you received as a christmas present recently. Also some cable ISPs in other countries still assign IPs to the WAN interface of their modems/routers according to the MAC address of the device.

Therefore, even TP-Link routers such as the WDR series or the Archer C7 allows to change or clone their MAC addresses. What's more, the MAC address of every Windows, Linux and MacOS system can be changed.

Beside this, I give you another example where it makes absolutely sense to be able to change the MAC address: Back in the 1990s a Taiwanese vendor (illegally) did clone Solaris workstations made by SUN Microsystems and sold them for a cheap price. They did even clone the MAC address of the system they used as the template system. Anyone who bought more than one system from this vendor couldn't use those systems in a network, since they all had the same MAC address. Without being able to change it, they would have wasted their money. ;)

For more valid reasons why it can make sense to change the MAC address of an interface, see: https://www.howtogeek.com/192173/how-and-why-to-change-your-mac-address-on-windows-linux-and-mac/

As for the legality of changing the MAC address: of course it is not illegal to change the MAC address of your own property. Please, guys, don't spread such rumors if you aren't sure or can't proof it by citing the law of some country which would forbid changing the MAC address.

As for the CPEs: it is not possible to change the MAC address through the web UI.

Carat1 wrote

Can you tell us what firmware you changed to?

OpenWRT/DD-WRT/LEDE. But this might be one-way until OEM-install will be fixed.

stell wrote

i change to LEDE Firmware...now can i change my wlan and lan mac add...my problem is to restore the original firmware..can't restore the original firmware..

As I said. The LEDE developers (which are former OpenWRT developers, BTW) screwed things up, so there currently is no way to re-install the original firmware. They should fix their firmware in order to allow re-installing original firmware or at least add a warning to their website/wiki for CPEs.