Hi Stephane, I think this is a result of a bug I already fixed, which barfed the security status after taking a query from the cache a second time. In your logs this seems to happen for in-addr.arpa.dlv.isc.org, which loses the secure status for its DLV answer, which in turn makes the DLV lookup error, which generates the servfail. Why the second lookup then succeeds I do not understand. I hope the bug is fixed in 1.3.1 (just with release candidate), otherwise I'd like to look at a higher verbosity log for it. Best regards and thanks for reporting, Wouter On 07/03/2009 03:04 PM, Stephane Bortzmeyer wrote: > I have "often" (I'm not sure how often) a SERVFAIL at the first reply, > then a normal answer immediately after. For instance: > > Unbound 1.3.0 on Debian/Linux, no forwarder, using dlv.isc.org. > > The log is attached. The first request is at 14:56:28, the second at > 14:56:36.