Solution:
Put mectric (lower prio first):
/etc/network/interfaces:
iface eth0 inet static
address 10.1.2.2
gateway 10.1.2.2
netmask 255.255.255.0
metric 100
iface eth1 inet static
address 192.168.0.186
gateway 192.168.0.185
netmask 255.255.255.248
metric 50