It looks like you aren't slurping the file, but I'm not entirely certain. If you aren't, something like:

my $lasttype = '';
while (<STDIN>) {
    s/\r|\n//gs;
      
    if ( /Host Name.*?:\s*(.*)$/ ) {
    $hostname = $1;
    print "$hostname\n";
    }
    if ( /DNS Servers.*?:\s*(.*)$/ ) {
    $dnsservers = [$1];
    print "$dnsservers\n";
    }
 
    if ( /Node Type.*?:\s*(.*)$/ ) {
    $nodetype = $1;
    print "$nodetype\n";
    }    

    if ( /(.*):/ ) {
        $lasttype = $1;
    } elsif ( $lasttype =~ /^DNS Servers/ && /\s*(.*)$/) {
        push @$dnsservers, $1;
    }
}
[download]

would work. Then $dnsservers is a hashref (see perldoc perlreftut if you don't know what a hashref is).