DEBIAN: Network configuration

Disable and remove NetworkManager:

sudo systemctl disable --now NetworkManager
sudo apt remove --purge network-manager

Add alternative names to the network interfaces:

# list devices
ip link
# identify ip addresses
ip addr
# set new alternative names for network interface
# ex: ip link property add eth0 altname wan
ip link property add <INTERFACE> altname <ALTNAME>

Now you can use the interface alternative name in and to name the interface configuration file <ifcfg-ALTNAME>

auto wan
# FOR DHCP
iface wan inet dhcp
	hostname <hostname> #optional
# FOR STATIC METHOD IPv4
iface wan inet static
	address x.x.x.x/x
    gateway x.x.x.x

# OPTIONAL 
	mtu 1500
    hwaddress xx:xx:xx:xx:xx:xx

Now you can use the interface <ALTNAME> in nftables

auto bond0
iface bond0 inet static
	bond-mode active-backup
	bond-miimon 100
	bond-primary wan1
	bond-slaves wan1 wan2
	address x.x.x.x/xx
	gateway x.x.x.x
	mtu 1500

Configure DNS

search  phys.ntnu.no. it.ntnu.no.
nameserver 129.241.0.200
nameserver 129.241.0.201
nameserver 1.1.1.1