jadedwench , 17 days ago

I am not at home, but what I did was change the 99-default.link file. I found this from the two pages below.
https://wiki.debian.org/NetworkInterfaceNames#CUSTOM_SCHEMES_USING_.LINK_FILES
https://wiki.debian.org/NetworkInterfaceNames

Basically, by doing this, your nic cards will be forcibly named using the mac address:

#/etc/systemd/network/99-default.link
 [Match]
 OriginalName=*

 [Link]
 NamePolicy=mac
 MACAddressPolicy=persistent

Afterwards, you will need to reboot and then update your network config file to use the correct names. I don't ever change the network config with the GUI in proxmox as it has wrecked it too many times. I will update this reply again later with some more information on what to do.