Operational Notification: LMDB integration problems with BIND 9.11.0 and 9.11.1


BIND 9.11.0 and 9.11.1 carries a number of integration problems with LMDB (liblmdb) that will be addressed in BIND 9.11.2.

Posting date: 
14 Jun 2017
Program Impacted: 
Versions affected: 
BIND 9.11.0 -> 9.11.1.Px (all versions of BIND 9.11.0 and 9.11.1)


ISC will be releasing BIND 9.11.2 in July/August 2017 which will address integration issues with BIND's use of LMDB in BIND 9.11.0 and 9.11.1.  Until then, our recommendation is that LMDB be disabled.

Use of LMDB for the 'New Zone Database" (NZD) is a new feature in BIND 9.11, introduced in order to provide significant performance improvements during dynamic zone handling.  It is enabled by default when building BIND on a system that has liblmdb installed and some packagers of BIND 9.11 include this feature (along with the liblmdb dependency) in their distribution.


Problems that may be encountered on servers with LMDB enabled and "allow-new-zones yes;" include:

  • Some new zones fail to persist following a restart, reload or reconfig
  • Zone deletions are incomplete leading to anomalies on restart and/or when re-adding zones
  • On a server that is started with the -u option, Issuing the commands "rndc reload" or "rndc reconfig" may result in named terminating unexpectedly
  • A deadlock (hang) of named sometimes occurs during concurrent dynamic zone operations


  • If building BIND 9.11 in an environment with liblmdb available, ensure that the integration is explicitly disabled by building BIND with the configure option --without-lmdb.
  • There are no run time options available to disable lmdb integration, therefore if you are running a pre-built (package) version of BIND 9.11.0 or 9.11.2 that provides LMDB integration along with installing liblmdb as a dependent package, we recommend contacting your provider to request an update.


BIND 9.11.2 will be published in July/August 2017.  At that time it will become available for download from http://www.isc.org/downloads/all.

Do you still have questions?  Questions regarding this advisory should go to security-officer@isc.orgTo report a new issue, please encrypt your message using security-officer@isc.org's PGP key which can be found here: https://www.isc.org/downloads/software-support-policy/openpgp-key/.  If you are unable to use encrypted email, you may also report new issues at: https://www.isc.org/community/report-bug/.

Note: ISC patches only currently supported versions. When possible we indicate EOL versions affected.  (For current information on which versions are actively supported, please see http://www.isc.org/downloads/). 

ISC Security Vulnerability Disclosure Policy:  Details of our current security advisory policy and practice can be found here: https://kb.isc.org/article/AA-00861/164/ISC-Software-Defect-and-Security-Vulnerability-Disclosure-Policy.html

This Knowledge Base article https://kb.isc.org/article/AA-01497 is the complete and official operational notification document.

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