## Release Notes for BIND Version 9.11.1b1

### Introduction

This document summarizes changes since the last production release on the BIND 9.11 branch. Please see the `CHANGES` file for a further list of bug fixes and other changes.

### Download

The latest versions of BIND 9 software can always be found at http://www.isc.org/downloads/. There you will find additional information about each release, source code, and pre-compiled versions for Microsoft Windows operating systems.

### License Change

With the release of BIND 9.11.0, ISC changed to the open source license for BIND from the ISC license to the Mozilla Public License (MPL 2.0).

The MPL-2.0 license requires that if you make changes to licensed software (e.g. BIND) and distribute them outside your organization, that you publish those changes under that same license. It does not require that you publish or disclose anything other than the changes you made to our software.

This new requirement will not affect anyone who is using BIND without redistributing it, nor anyone redistributing it without changes, therefore this change will be without consequence for most individuals and organizations who are using BIND.

Those unsure whether or not the license change affects their use of BIND, or who wish to discuss how to comply with the license may contact ISC at https://www.isc.org/mission/contact/.

### Security Fixes

- A coding error in the `nxdomain-redirect` feature could lead to an assertion failure if the redirection namespace was served from a local authoritative data source such as a local zone or a DLZ instead of via recursive lookup. This flaw is disclosed in CVE-2016-9778. [RT #43837]

- named could mishandle authority sections with missing RRSIGs, triggering an assertion failure. This flaw is disclosed in CVE-2016-9444. [RT #43632]

- named mishandled some responses where covering RRSIG records were returned without the requested data, resulting in an assertion failure. This flaw is disclosed in CVE-2016-9147. [RT #43548]

- named incorrectly tried to cache TKEY records which could trigger an assertion failure when there was a class mismatch. This flaw is disclosed in CVE-2016-9131. [RT #43522]

- It was possible to trigger assertions when processing responses containing answers of type DNAME. This flaw is disclosed in CVE-2016-8864. [RT #43465]

- Added the ability to specify the maximum number of records permitted in a zone (`max-records #;`). This provides a mechanism to block overly large zone transfers, which is a potential risk with slave zones from other parties, as described in CVE-2016-6170. [RT #42143]

### Feature Changes

- Expanded and improved the YAML output from dnstap-read -y: it now includes packet size and a detailed breakdown of message contents. [RT #43622] [RT #43642]

- If an ACL is specified with an address prefix in which the prefix length is longer than the address portion (for example, 192.0.2.1/8), named will now log a warning. In future releases this will be a fatal configuration error. [RT #43367]

### Bug Fixes

- Referencing a nonexistent zone in a response-policy statement could cause an assertion failure during configuration. [RT #43787]

- rndc addzone could cause a crash when attempting to add a zone with a type other than master or slave. Such zones are now rejected. [RT #43665]

- named could hang when encountering log file names with large apparent gaps in version number (for example, when files exist called "logfile.0", "logfile.1", and "logfile.1482954169"). This is now handled correctly. [RT #38688]

- If a zone was updated while named was processing a query for nonexistent data, it could return out-of-sync NSEC3 records causing potential DNSSEC validation failure. [RT #43247]

### Maintenance

- The built-in root hints have been updated to include an IPv6 address (2001:500:12::d0d) for G.ROOT-SERVERS.NET.

### Miscellaneous Notes

- Authoritative server support for the EDNS Client Subnet option (ECS), introduced in BIND 9.11.0, was based on an early version of the specification, and is now known to have incompatibilities with other ECS implementations. It is also inefficient, requiring a separate view for each answer, and is unable to correct for overlapping subnets in the configuration. It is intended for testing purposes but is not recommended for for production use. This was not made sufficiently clear in the documentation at the time of release.

### End of Life

The end of life for BIND 9.11 is yet to be determined but will not be before BIND 9.13.0 has been released for 6 months. https://www.isc.org/downloads/software-support-policy/

### Thank You

Thank you to everyone who assisted us in making this release possible. If you would like to contribute to ISC to assist us in continuing to make quality open source software, please visit our donations page at http://www.isc.org/donate/.