On host and pi zero

On host /etc/network/interfaces
source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
#Line below doesn't work, hangs the system on startup
#iface eth0 inet6 dhcp

auto usb0
allow-hotplug usb0
iface usb0 inet static
        address 192.168.123.111
        netmask 255.255.255.0


On Pi Zero /etc/network/interfaces

# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto lo
iface lo inet loopback

auto usb0
allow-hotplug usb0
iface usb0 inet static
        address 192.168.123.111
        netmask 255.255.255.0
        gateway 192.168.123.156

allow-hotplug wlan0
iface wlan0 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

allow-hotplug wlan1
iface wlan1 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

$ sudo ip route show dev usb0
192.168.123.0/24  proto kernel  scope link  src 192.168.123.111

$ sudo ip a && sudo ip route
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether b8:ac:6f:2e:69:3c brd ff:ff:ff:ff:ff:ff
    inet 192.168.123.156/24 brd 192.168.123.255 scope global dynamic eth0
       valid_lft 41932sec preferred_lft 41932sec
    inet6 fe80::baac:6fff:fe2e:693c/64 scope link 
       valid_lft forever preferred_lft forever
5: usb0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 12:2d:9e:ce:05:eb brd ff:ff:ff:ff:ff:ff
    inet 192.168.123.111/24 brd 192.168.123.255 scope global usb0
       valid_lft forever preferred_lft forever
default via 192.168.123.254 dev eth0 
default via 192.168.123.254 dev eth0  proto static  metric 1024 
192.168.123.0/24 dev eth0  proto kernel  scope link  src 192.168.123.156 
192.168.123.0/24 dev usb0  proto kernel  scope link  src 192.168.123.111