I forgot an important part, your query proxy has still no rate limit. It can be used to flood spoofed IP's.
> Hi, > > If you are on the hlds windows mailing list, then you probably already > know > about A2S_INFO DDOS attacks. I have mistakenly posted a *fix* on the list > for *nix servers which I should have posted here. > > In short: > If your server gets ddosed with A2S_INFO packets, it will get really > laggy. > Setting sv_max_queries_sec to a low value will make the server disappear > from the server browser list. I'm providing you with a UDP Caching Proxy > which will query the server with A2S_INFO requests not more than once in a > five seconds and respond to the client with the cached data. > > Setup: > 1. Get the source from http://www.gign.lv/tmp/querycache.c > 2. Compile with gcc querycache.c -o querycache > 3. Open an UDP port in firewall for the proxy server, lets say 21015 > 4. Make sure you have iptables NAT, REDIRECT and string match support > compiled into kernel or as modules > 5. execute: iptables -t nat -A PREROUTING -p udp -d > YOUR_EXTERNAL_TF2_SERVER_IP --dport YOUR_SERVER_PORT -m string --algo kmp > --string 'TSource Engine Query' -j REDIRECT --to-port 21015 > 6. Run querycache (probably under screen, so you can detach from it) > > I've been ddosed with about 300req/sec and it works good, however I don't > give any warranty that it will work for you. > _______________________________________________ > To unsubscribe, edit your list preferences, or view the list archives, > please visit: > http://list.valvesoftware.com/mailman/listinfo/hlds_linux > _______________________________________________ To unsubscribe, edit your list preferences, or view the list archives, please visit: http://list.valvesoftware.com/mailman/listinfo/hlds_linux
