auto lo

iface lo inet loopback

auto eth0

iface eth0 inet static
  address {{ ansible_host }}/{{ netmask }}
  routes-static {{ gateway }},default via {{ gateway }}

{% if ip6 is defined %}
iface eth0 inet6 static
  address {{ ip6 }}/{{ netmask6 }}
  gateway {{ gateway6 }}
  pre-up echo 0 > /proc/sys/net/ipv6/conf/eth0/accept_ra
{% endif %}