> Hey Squid users :) > > We had a problem recently where a user with a misconfigured download > accelerator was able to bring our proxy to its knees, downloading an > 80MB driver about 100 times in parallel. We temporarily solved the > problem by stopping the download accelerator, but this makes me aware > of how vulnerable our proxy is to heavy DOS-type attacks. > > I've read a bit about the partial object caching expected in 3.1, > range_offset, and half-closed clients. Can anybody share some ideas > for making a squid cache more resilient to this kind of abuse / attack? >
The 'maxconn' ACL is available in all squid to protect against this type of client. The collapsed forwarding feature of 2.x designed to cope with wider DDoS still needs someone with time to port it into 3.x. http://wiki.squid-cache.org/Features/CollapsedForwarding Amos
