127.0.0.1 localhost
{{ ansible_eth0.ipv4.address }}  {{ ansible_hostname }}

{% for host in groups['all'] %}
{{ hostvars[host].ansible_eth0.ipv4.address }}  {{ hostvars[host].ansible_hostname }}
{% endfor %}

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts