$ORIGIN _ips.example.
$TTL 300
@          IN SOA ns.example. mail.example. ( 1 3600 900 604800 300 )
@          IN NS  ns.example.

; Synthesis targets used by the alias zones.
web        IN A    192.0.2.1
web        IN AAAA 2001:db8::1
alt        IN A    192.0.2.2
mail       IN A    192.0.2.3
mail       IN MX   10 mx.example.