Mastering NetScaler VPX™

HTTP DoS protection

In some cases, it might not be that easy to detect an attack. For instance, in a HTTP DDoS attack, a web server might be attacked with legitimate traffic; therefore they are regular HTTP requests. This is where we can use HTTP DoS protection. HTTP DoS protection allow NetScaler to respond with a JavaScript challenge to all incoming HTTP requests. Since a HTTP DDoS attack is typically done using a cluster of many nodes running a scripted attack, these nodes do not support any form of JavaScript request; therefore, when they cannot respond to the JavaScript challenge, NetScaler closes the connection. Regular users surfing with a regular browser support JavaScript and are therefore granted access. This happens in the background ...