[tor-relays] Dynamic IP

[Tim]

> On Sun, 17 Aug 2014 00:42:13 +0200, Sebastian Hahn <mail at sebastianhahn.net> wrote:
> 
> Date: Sun, 17 Aug 2014 00:42:13 +0200
> From: Sebastian Hahn <mail at sebastianhahn.net>
> To: tor-relays at lists.torproject.org
> Subject: Re: [tor-relays] Dynamic IP
> Message-ID: <90ABDCE9-CC09-4892-9935-F7B7C78832E9 at sebastianhahn.net>
> Content-Type: text/plain; charset=us-ascii
> 
> Hi Tim,
> 
>> On 16 Aug 2014, at 23:53, Tim <t_ebay at icloud.com> wrote:
>> I'm running a relay on a similarly "dynamic" IP.
>> If the line goes down, I'm reallocated a new one. But otherwise the IP is stable.
>> If I don't notice the change, I notice the traffic drop, then I update the torrc, and everything works again.
> 
> I think you're a little confused. It's not necessary to specify your own
> IP address in Tor's configuration file. The various "address" options are
> purely optional. Or I am confused, and you mean something completely
> different?
> 

Sebastien, I run a relay on a machine that has an internal private IP, behind a NAT router with a public IP.

In my experience, I need to specify the NAT router's public IP in the torrc, otherwise tor doesn't include it in the router descriptor it submits to the consensus.

How does tor autodetect its public IP, when it is running on a separate machine with a private network IP, behind a NAT router with a public IP?

If that process isn't working for me, is this a bug I should report?

If tor doesn't currently autodetect public IPs on middleboxes (as opposed to the tor relay machine itself), is this a feature that could be implemented?
Or do we wish to discourage this use case?
(It would involve trusting an external server to report tor's public IP correctly - and making other assumptions like the middlebox having a single public IP.)

Tim