Hello Mark, similar problem can be reproduced on recursive non-forwarding server by setting "max-cache-ttl" to some low value (in production I have 3600, for quick reproduction set it to 10) and sending query "in the last second of TTL", for example:
== code begin == while true; do dig -p 5353 @localhost www.seznam.cz. +noauthority +noadditional 2>/dev/null | grep -E "^www\.seznam\.cz\.|SERVFAIL"; sleep 10.1; done == code end == In addition to SERVFAIL, sometimes it is accompanied with warning: "checkhints: unable to get root NS rrset from cache: not found" (IMHO, this should never happen.) The behavior is reproducible on 9.10.4 and 9.10.4-P1. I am unable to reproduce it on 9.11.0b1. After a brief look at the source diffs (especially lib/dns/rbtdb.c) between 9.10.3-P4, 9.10.4(-P1) and 9.11.0b1, it seems to me like a problem related to changed handling of "just expiring" records in 9.10.4 [RT #41687]. Brgds, Ondrej -----Original Message----- From: bind-users-boun...@lists.isc.org [mailto:bind-users-boun...@lists.isc.org] On Behalf Of Mark Andrews Sent: Monday, June 20, 2016 8:39 AM To: Thomas Sturm Cc: bind-us...@isc.org Subject: Re: Issues resolving outlook.office365.com A fix for this is in review and should be in the next maintainance release. Mark In message <16a2cdfd-694d-444a-a760-17c9d7517...@open.ch>, Thomas Sturm writes: > > I am now able to reliably reproduce the behaviour with dig querying > BIND > 9.10.4-P1 (not 9.9, apparently) with "prefetch 0b _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users