There are a few mistakes in your code:

1. You should specify local port and SO_BROADCAST flag
2. Use $@ to output error message from new()
3. recv returns the addres of sender

So, here is my code:

my $sock1 = IO::Socket::INET->new(
    LocalPort  => 9897,
    PeerAddr  => inet_ntoa(INADDR_BROADCAST), # you may use '127.0.0.1
+' for local host
    Proto     => 'udp',
    LocalAddr => '127.0.0.1',
    Broadcast => 1 );

die "Can't bind to $udpcon: $@\n" unless $sock1;

my $data;
my $addr;

print "waiting for data on $udpcon ...\n";

while (1) {
  $addr = recv($sock1, $data, 10, 0);
}
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