Re: another unusual connection

["Andrew S. Lists" <lists@xxxxxxxxxxx>]

On Sun, 10 Feb 2008 01:47:01 -0600, Scott Bennett wrote:
>      But, Roger, will the 0.2.0.19-alpha release at least confirm during
> the reachability tests that it is talking to itself and not to some other
> server?

I am not sure that is what is happening. For example, it may be that the
reachability checks are being performed on the current (and correct) IP
before the update to the suggested new IP is put into effect.

Anyway, I suggested making an explicit verification of the reachability
of the current IP before updating to a suggest new IP as a means to help
counter incorrectly suggested new IPs. E.g., if the old IP still works,
ignore the suggested new IP; if the old IP does not work, update to the
suggested IP. (This sort of thing doesn't solve the root issue of how
best to establish trust in the IP address observations of directory
servers, but maybe it helps a bit. Once you get an accurate IP
suggestion, you are protected against incorrect suggestions until such
time as you become unreachable again, when the game starts all over and
you were back down anyway.)

There are probably many ways to perform that check - one way I threw out
there was to explicitly call the check reachability routines before
updating; another (and perhaps better) way might be to only process
suggested new IPs when Tor notices that it is no longer reachable.

Unfortunately, neither did I supply a working patch to implement
explicit verification of the old IP as an additional workaround for the
root issue nor did I even confirm the cause of the successful
reachability tests.

Scott, you have been quite vocal in this area, so perhaps you might want
to put in some legwork here. I am sure the Tor team (and the rest of us)
would appreciate such efforts.

-Andrew