The entire time the forum was down I had no trouble establishing an open circuit to dkn255hz262ypmii.onion. I even closed the open circuits I established a few times and rinsed and repeated, and never had any trouble establishing an open circuit. The problem was that streams through the circuit were going from connecting to closing almost immediately, without ever opening. That is indicative of Tor on the hidden service redirecting traffic to a port that has nothing listening on it. Do an experiment, configure a hidden service yourself but don't run anything on the port that you have it redirect traffic to. Now connect to the hidden service. You will see the same exact behavior, the circuit is established without problems, but the streams through the circuit quickly go from connecting to closed. I am pretty much absolutely certain that the actual forum server did not experience any down time, and I am equally certain that the introduction nodes behaved correctly and were not DDoSed. Tor on the remote server (dkn255hz262ypmii.onion) was running and operating perfectly for the entire duration of the down time (that I witnessed anyway, which was quite a while but probably not from the very start). The problem was that it was redirecting traffic to a port that had nothing listening on it, or something malfunctioning listening on it. This means that the problem was with Apache (and very likely it had crashed). Towards the end of the down time Apache started working correctly, because the streams were going from connecting to open to closed, and a 500 error was returned on valid pages and 404 on invalid pages. This suggests to me that the problem at this point was with PHP, but it could have been an Apache problem as well. It looked like Apache kept crashing and coming back up, because it would go from rarely loading with a 500 internal server error, to forming a circuit to the remote instance of Tor, but with streams through it going from connecting to closed. I am positive that the server hosting this forum did not go down nor was it overwhelmed with bandwidth. I am also 100% positive that the introduction nodes were not DDoSed. I am less sure, but still quite confident, in saying that the down time was caused by Apache crashing.