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I am running an online game for kids but lately I have been experiencing attacks from some vile individuals who just like ruining it. I assume (based on Windows log) that they connect hundreds time with resending the packets so the server runs out of tcp connection slots. The server (software for that game) disconnects these unassigned connections after like 5 seconds, but recieving thousands of messages, it gets jammed. My only idea is - could a proxy (HW or SW) be used for filtering incoming traffic from particular IP? So these data would never reach the server. Thanks

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You need to confirm the failure mode or your solution is not very likely to work. Is the server running out of connection slots? Or is the network bandwidth getting maxed inbound? Or maxed outbound? Or are they issuing commands that load the server? Or what? – David Schwartz Mar 15 '12 at 10:22
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You could use a reverse proxy to achieve what you want, provided you are running a web based application, however this just shunts the effort onto the proxy, and it isn't the ideal solution for your problem.

This type of problem is usually solved by using a firewall. All firewalls can filter IP addresses, or ranges of IP addresses, and if you are running an online service such as you describe, it is definitely something that should be in the mix.

Additionally, a modern full featured firewall can also automatically block IP addresses with excessive open connections, to a threshold you define. This eliminates the need to continually and manually "chase" malicious activity that may change IP addresses to work around any hardcoded blocks.

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thank you. It is not a web game, its a desktop server/client online game. Could you suggest me a free solution if you know any? The closing IP addressed with excessive connections sounds like my salvation. – TheP Mar 15 '12 at 8:07
It is difficult to recommend anything without knowing the environment. If you are using a web host, they should be able to provide a firewalling option. Otherwise if it is your environment, then a linux machine + could do what you need – Paul Mar 15 '12 at 8:15
I am running at one of my computers at home. WinXp – TheP Mar 15 '12 at 8:16
Most domestic routers allow blocking of IP addresses. Windows XP also has a firewall built in which can block incoming IP addresses. – Paul Mar 15 '12 at 8:24
thanks, I am particularly interested in blocking automatically these with too many open ports – TheP Mar 15 '12 at 8:26

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