Hi,
tonight I wanted to upgrade my Proxmox VE 6.4 to version 7. Following the instructions under https://pve.proxmox.com/wiki/Upgrade_from_6.x_to_7.0#Linux_Bridge_MAC-Address_Change I adjusted /etc/network/interfaces from
root@proxmox-ve6:/# cat /etc/network/interfaces
auto lo
iface lo inet...