Changing network configuration

Hello,

What’s the recommended approach for persistently changing network settings?

We’d like to set the MTU size:

sudo ifconfig eth0 down
sudo ifconfig eth0 mtu 8164
sudo ifconfig eth0 up

We’d like these to be applied on startup, I believe the correct way is to edit the network config files. I wasn’t able to find evidence of netplan or networkmanager cfg files in the obvious spots. Where’s the correct place to edit this? I’m mindful of not conflicting or interrupting any built-in farm ng network settings.

Thanks,
Steven