This Tutorials shows, how you can easily take out an Apache Webserver with one HTTP POST Tool using a std. slow DSL Connection.

This is NO Slowloris Attack!
Limitations of HTTP GET DDOS attack:

- Does not work on IIS web servers or web
servers with timeout limits for HTTP headers.

- Easily defensible using popular load balancers,
such as F5 and Cisco, reverse proxies and
certain Apache modules, such as mod_antiloris.

- Anti-DDOS systems may use "delayed
binding"/"TCP Splicing" to defend against HTTP
GET attacks.

Why HTTP POST DDOS attack works

- This attack can evade Layer 4 detection
techniques as there is no malformed TCP, just
like Slowloris.

- Unlike Slowloris, there is no delay in sending
HTTP Header, hence nullifying IIS built-in
defense, making IIS vulnerable too.

- Size, character sets and time intervals can be
randomised to foil any recognition of Layer 7
traffic patterns by DDOS protection systems.

- Difficult to differentiate from legit connections
which are slow

Download OWASP HTTP Post Tool