I’m using android phone as red (usb tethering) but the problem is each time when I connect my phone, the mac address changes and ipfire doesn’t recognise it as red0.
Any solution to this problem?
In Android 10 they introduced the randomised mac address and made it the default. However you can still choose to have the device mac which is then consistent.
In the device settings for the wireless connection you are using there is an entry on my phone called MAC address type and it has Use randomised MAC (default) and Use device MAC. Select the Use device MAC and it will then stay constant.
The exact location in the menu structure may be slightly different depending on the phone you have but it will somewhere around the settings or advanced settings for the wireless connection you are using.
wifi tethering same to be fine for me but the usb tethering is one with such problem.