[Gta04-owner] How to automate setting IP on cdc_ether netdev

[Neil Jerram]

Does someone know how I can most easily automate setting IP 
192.168.0.200 on the cdc_ether device that I get (on my laptop) when 
connecting my GTA04 over USB?

At the moment:

- I'm getting a device named enp0s20u2, with an apparently random MAC 
address.

- Because the MAC address is different each time (I think), Network 
Manager thinks it's a different connection each time.

- Manual setting with 'ip a a 192.168.0.200/24 dev enp0s20u2' doesn't 
stick, because Network Manager is managing the device.

- Hence I keep having to edit the connection settings in Network Manager 
- which is a pain!

Suggestions?

Thanks - Neil