Re: Tor and NNTP

[Matt Ghali <matt@xxxxxxxxx>]

On Fri, 3 Nov 2006, Aioe wrote:

> In order to avoid SYN DDOS and floods, my server accepts only a determinate
> number of daily connections and bytes per IP. Trespassers are banned for a
> day. While a single (end) proxy serves a single client the total activity
> generated on my host by that tor router usually remains under this limit.
> When more than a client uses the same proxy, often that tor router exceeds
> those values because the barrier is calibrated assuming a single client per
> IP. Every IP can also post only 25 messages per day which is a reasonable
> limit for a single client but it isn't enough when multiple users share the
> same IP.

There is a fundamental flaw in this assumption that will cause you 
problems with a much larger user set than just tor users. Your 
assumptions on a 1:1 mapping of users to ip addresses also break for 
populations behind NAT. Sometimes entire organizations or networks 
appear to the public internet as a single set of proxy/NAT 
addresses, and your accounting method breaks for this set as well.

While explicitly permitting Tor routers is a step in the right 
direction, you're going to run into the same problems with natted 
users, and that will be a tougher nut to crack.

good luck,
matto

--matt@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<darwin><
  Moral indignation is a technique to endow the idiot with dignity.
                                                - Marshall McLuhan