There are two NICs eth0 and eth1 (on Raspbian buster). For eth0 DHCP is used which works fine. eth1 is supposed to be up but otherwise go untouched (NO static address since I‘m trying to setup my own PPPoE server on eth1).
Setting eth1 to manual in /etc/network/interfaces doesnˋt work as it also gets an address. It seems the way NICs are configured has changed since wheezer but all examples I found relate only to configuration of static addresses.
So how can DHCP (eth0) and manual (eth1) be configured at the same time?