What does "nt ring" show (on this node and on the other two)?

That may provide some clues.

From: Patricio EchagŁe <patricioe@gmail.com>
Reply-To: <user@cassandra.apache.org>
Date: Sun, 2 Sep 2012 15:50:31 -0700
To: <cassandra-user@incubator.apache.org>
Subject: Repair has now effect

Hey folks, perhaps a dumb question but I ran into this situation and it's a bit unclear what's going on.

We are running a 3 nodes cluster with RF 3 (cass 1.0.11). We had one issue with one node and it was down for like 1 hour.

I brought the node up again as soon as I realized it was down (and ganglia + nagios triggered some alerts). But when running repair to make sure it had all the data, I get this message:

 INFO [AntiEntropySessions:6] 2012-09-02 15:46:23,022 AntiEntropyService.java (line 663) [repair #%s] No neighbors to repair with on range %s: session completed

Am I missing something ?