Usage of ISP Proxys and DNS resolvers

Tue Apr 22 16:24:08 UTC 2003

On Tue, 22 Apr 2003, Maximillian Dornseif wrote:

> 
> I like to get an estimate if the percentage of users
> 
> 1. Using their Providers HTTP-Proxy to surf the web

Well if its forced, a transparent proxy.. you could do what you suggest below. 
It appears to be common place, seemingly more so amongst the larger access
providers (residential?) to do this..

> 2. Using their Providers DNS-Servers/recursive resolvers to resolve DNS 
> queries

Again, if you want to enforce the idea you can force DNS also..

Of course if you want to filter certain IPs, why not do it in routing rather 
than messing with these applications?

Bit of a can of worms if you ask me tho.. censorship, freedom of speech, and 
once you start actively policing you need to keep it up else surely your liable 
if you allow a bit of the type of content through that your aiming to stop? (eg 
if you claim your dialup is children safe then allow porn thro that makes you at 
fault, at least being a pure "network operator" keeps you out of this legal 
mess)

Steve

> 
> 
> Background:
> 
> I'm writing a research paper on government mandated web filtering in 
> germany (see http://www.politechbot.com/p-03983.html for an overview on 
> the matter). Basically the government want's censorship done by 
> blocking IP-Addresses, faking DNS entries or doing filtering at 
> http-proxy level.
> 
> Trying to determine the effect of this approaches on the average user 
> it is important to know how many users would be affected by this 
> measures. I guess:
> 
> * Users with leased lines usually do not use the providers proxy
> * Dial-in/DSL users with use a provider supplied setup-tool usually 
> don't change the preset staying with using the Proxy.
> * Big Customers with many users might run their own DNS resolver
> * Most other users use their ISPs DNS resolver
> 
> I would be most grateful if someone could provide me with actual 
> numbers on this or at least an educated guess. If you think there is a 
> better place to look for this numbers I would be most grateful if you 
> point me there.
> 
> If you wish reply directly to me - I will post a summary.
> 
> Best Regards
> 
> Max Dornseif
> 
> 