Are you certain it is a ddos? Does your inbound bandwidth actually spike? Most games have a myriad of network code bugs that can cause a client to crash with

Are you certain it is a ddos? Does your inbound bandwidth actually spike? Most games have a myriad of network code bugs that can cause a client to crash with a specially crafted packet. Sometimes it is as simple as disabling automatic port forwarding on your ISP/home router sometimes also called UPNP or SSDP in the router unless you are the one hosting the "game server". Beyond that my answer would require some knowledge of capturing packets and looking for anomalies just before the client crash which would exceed the requirements you stated. Try disabling UPNP/SSDP on your router, then updating the firmware on your router and rebooting it. If that is not an option then read up on how to modify the firewall rules of your OS to disable the inbound ports for your game as they are only required if you are hosting a public server. If they are killing the connection on the server side then the only thing one could do is to not use that server. This is common on servers hosted by the players. Try to release and renew your DHCP lease on the router if it has the option. Sometimes turning it off a while and back on will do this varies by ISP with the goal being to get a new IP so they stop booting or punting your IP address and game port(s) provided you do not reconnect to the servers operated by the cute and fuzzy bunnies.