Node restart UDP server - node.js

Question

I'm creating a udp server for receiving a message and sending a response quickly.
I find myself, however, to have a problem: the server can not close the connection to the client once it has been answered.
So, to avoid saturating the server, I thought of a way to restart the server udp (a sort of re-bind), once a counter has reached a certain number, but I can not find a solution to close the server udp and restart it.
Is there a way to do this?
Here a code snippet example of what I have at the moment:
/** Udp server */
var reset = function() {
if(count > 3) {
server.close();
count = 0;
console.log('reset');
server.bind('4002');
}
return true;
};
var count = 0;
var server = require("dgram").createSocket("udp4");
server.on("message", function(message, requestInfo) {
count++;
message = message.toString();
if(message == null || message === '') {
reset();
return;
}
// do something with the received message and sends the reply ..
var response = new Buffer(result.toString());
server.send(response, 0, response.length, requestInfo.port, requestInfo.address);
reset();
}
);
server.on("error", function(error) {
console.log(error);
server.close();
});
server.on("listening", function() {
var address = server.address();
console.log("server listening " + address.address + ":" + address.port);
});
server.bind('4002');
This is the stack trace:
events.js:72
throw er; // Unhandled 'error' event
^
Error: Not running
at Socket._healthCheck (dgram.js:420:11)
at Socket.bind (dgram.js:160:8)
...