without reviewing all the code but just the error you got it seems that the module complains about the (local) address (and port!) are already in use. It is reasonable.

You can make the local port ( $lport ) a parameter to the script passed as $ARGV[1] ad open that port locally.

After this a little wrapper that call the script each time (16+ million times..) with a new IP and a new port it's a simply thing.

L*