use Net::Ping;

# fill this array with your ips
my @ips = map { "192.168.1." . $_ } ( 2 .. 254 );
my @ips_up;

use constant { TIMEOUT => 5000, PORT => 7 };
my $p = Net::Ping->new( "syn", TIMEOUT() / 1000 );
$p->{port_num} = PORT;

$p->ping($_) for (@ips);
while ( my ( $host, $rtt, $ip ) = $p->ack ) {
  push @ips_up, $ip;
}

local $" = "\n";
print @ips_up;