[tor-relays] Advantage in more exits in the same /8?

[Jonathan D. Proulx]

On Wed, Aug 27, 2014 at 08:44:50AM -0600, Jesse Victors wrote:

:Anders, no I literally mean the same /8. The university has its own /16 and recently required another /16, but since my nodes are physically close to one another they are in the same /8. My concern is that too many nodes in a small block can result in a large concentration of Tor circuits in that block. No circuit should use any two nodes from the same /16 unless forced to, so my question really revolved around how many is too many Tor circuits and how much is too much traffic through the same /8 or /16 in people's opinion.

Not to drift too far off course, but I think you have your masking
back wards or confused at least.

a /8 is 16M addresses 18.0.0.0/8 for example, so not a small block,
and a /16 has 64K.

two consecutive /16's say 128.30.0.0/16 and 128.31.0.0/16 make a /15
(120.30.0.0/15)

the real concern is administrative control not addressing. for exmaple
both the /8 and /15 mentioned above and some other smaller patches of
addressing are all on MIT campus and part of the same administrative
domain in the sense that all traffic passes through a small set of
routers at some point.  Being a university it doesn't imediately imply
root access to all servers.  this isn't true of all (or even most)
/8's, nor does even a /24 with 256 addresses need to be in a single
geographic or andministrative zone.

-Jon