auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 1.2.3.4
netmask 255.255.255.0
gateway 4.3.2.1
auto eth0:1
iface eth0:1 inet static
address 1.2.3.5
====RENDERED-INTO=========================================
auto lo
iface lo inet loopback
iface eth0 inet manual
auto test-br-eth0
iface test-br-eth0 inet static
address 1.2.3.4
netmask 255.255.255.0
gateway 4.3.2.1
bridge_ports eth0
up ip link set eth0 up
pre-up ip link add dev eth0 name test-br-eth0 type bridge || true
auto test-br-eth0:1
iface test-br-eth0:1 inet static
address 1.2.3.5