On Sat, Apr 09, 2011 at 04:23:21PM -0400, cmeclax-sazri wrote:

Suppose I have this setup: Dhole, Dingo, and Fennec are three computers on a LAN. Dhole and Dingo both have external IP addresses and both run Tor relays. Fennec runs a hidden service. Both Dhole and Dingo have the same hidden service address, paxamifrabolerfu.onion, pointing to Fennec's LAN address. Alice tries to connect to paxamifrabolerfu.onion. What happens?

First, it doesn't matter if they're relays or clients. Hidden services don't need to be on a relay.

The answer if two different Tors have the same hidden service private key is that they will each publish a hidden service descriptor. Whichever one published more recently is the one that a user accessing the hidden service will probably find and use.

This approach can provide a very crude load balancing. More interesting, it can also provide a very crude failover, where if one of them disappears, an hour or so later the other will publish and the hidden service will become reachable again.

--Roger