use strict;
use warnings;
use Data::Dump::Streamer;
use YAML ();

my $yamlStr = <<END_YAML;
---
host_1: "192.168.1.1"
host_2: "192.168.1.2"
host_3: "192.168.1.3"
---
-
    - host_1
    - "192.168.1.1"
-
    - host_2
    - "192.168.1.2"
-
    - host_3
    - "192.168.1.3"
END_YAML

my ($IPMapH, $IPMapAoA) = YAML::Load ($yamlStr);

Dump $IPMapH;
Dump $IPMapAoA;