To be more precisely:
When a TCP/IP connection is established the client side of the connection uses a port number. Unless a client program explicitly requests a specific port number, the port number used is an ephemeral port number. Ephemeral ports are temporary ports assigned by a machine's IP stack, and are assigned from a designated range of ports for this purpose. When the connection terminates, the ephemeral port is available for reuse, although most IP stacks won't reuse that port number until the entire pool of ephemeral ports have been used. So, if the client program reconnects, it will be assigned a different ephemeral port number for its side of the new connection.
All-in-one "home" modems/routers are ready to use for average costumers/users without deep knowledge of Ethernet technology. Software/hardware developers are forced to deal with various needs and requierments unless they develop their stuff for certain applications with skilled and trained users. I guess a professional router with firewall or DMZ would provide a more appropriate setting of DoS attack protection.
@Mark, HB9AZT
I knew that I'm not the only user with these kind of problems ...
![Wink ;)](https://www.remoterig.com/forum/Smileys/default/wink.gif)
Mike