Added example answer

.gitignore

@@ -0,0 +1,2 @@
+*.sum
+goudpserver

main.go

@@ -17,6 +17,12 @@ func lstn(connection *net.UDPConn, alarm chan struct{}) {
 	for err == nil {
 		n, remoteAddr, err = connection.ReadFromUDP(buffer)
 		fmt.Println("from", remoteAddr, "-", buffer[:n])
+		n, err = connection.WriteToUDP([]byte("OK"), remoteAddr)
+		if err != nil {
+			fmt.Println("WriteUDP Error (", err.Error(), ")")
+		} else {
+			fmt.Println("WriteUDP... OK")
+		}
 	}
 
 	fmt.Println("Listener failed (", err, ")!")