Preventing Abuse

TimeOut LimitRequestBody LimitRequestFields LimitRequestFieldSize LimitRequestLine LimitXMLRequestBody

Denial of service (DoS) attacks work by swamping your site with a great number of simultaneous requests, slowing down the server or preventing access altogether to legitimate clients. DoS attacks are difficult to prevent in general, and usually the most effective way to address them is at the network or operating system level. One example is blocking specific addresses from making requests to the server; although you can block those addresses at the web server level, it is more efficient to block them at the network firewall/router or with the operating system network filters.

Other kinds of abuse include posting extremely big requests or opening a great number of simultaneous connections. You can limit the size of requests and timeouts to minimize the effect of attacks. The default request timeout is 300 seconds, but you can change it with the TimeOut directive. A number of directives enable you to control the size of the request body and headers: LimitRequestBody, LimitRequestFields, LimitRequestFieldSize, LimitRequestLine, and LimitXMLRequestBody.