Recently I did some consultancy work with a client who was used as a second hop in a DNS amplification attack and I've taken a bit of an interest in this phenomenon. So much interest in fact that I ran some experimentation of my own as to how easy it is to carry out this kind of attack. The results of my experiment follow in the rest of this post. I should forewarn that this is an extremely techie blog post so isn't for the faint hearted!