I have a HS server for web proxying purposes with an onion address. It's in a test phase at the moment and traffic is low, but from time to time the web server is not reachable using Tor Browser, however it is still accessible from a clearnet browser. I have checked Tor logs during connection breakdown:
Dec 28 11:05:09.000 [notice] Bootstrapped 100%: Done Dec 28 12:15:36.000 [notice] Tor has not observed any network activity for the past 632 seconds. Disabling circuit build timeout recording. Dec 28 12:15:36.000 [notice] Tor now sees network activity. Restoring circuit build timeout recording. Network was down for 632 seconds during 1 circuit attempts.
Restarting Tor and then Nginx solves the problem. What else can I check to figure out where the problem is, or how to fix it. I don't know if it's relevant but IPv6 routing is not working because my hosting provider doesn't support it yet.
Server is Ubuntu 14.04, Tor v0.2.7.6, nginx/1.4.6