Hi Jesse,

On 08/26/2014 03:47 PM, Jesse Victors wrote:

It seems to me that too many nodes under the same ISP is problematic because it concentrates too much traffic in the same AS, but on the other hand, Tor could use more exits. More importantly, how many is too many nodes in the same /8, or in the same /16? Where would you draw the line?

Very good question. Ideally, the Tor client would be AS-aware, and you would not have to worry about it. For the interested reader, see for example [1]. Until then, my thinking is that I compare to other locations. https://compass.torproject.org/ is very helpful for that: For example, if you group by AS, the largest AS right now (i3d, NL) in regards to exit capacity has 11%, and OVH tops the overall network at 10% consensus weight.

As a rough rule, I'd avoid to push more than 1-2Gbit/s of traffic at one ISP. On the plus side, as long as you don't top the list, you're weighing down other locations. And universities are a preferred location.

Make sure to use the MyFamily statement correctly: Unless relays are on the same /16, Tor might pick multiple of them for a circuit. Also, if you want to push more than ~100 Mbit/s on a single machine, you need AES-NI or run multiple relays, for more than 400 Mbit/s you need to run multiple relays in any case. The multi-relay initscript can be quite helpful for that.

[1] http://freehaven.net/anonbib/#ccs2013-usersrouted [2] https://www.torservers.net/wiki/setup/server#multiple_tor_processes