## Release Notes for BIND Version 9.9.8b1

### Introduction

This document summarizes changes since the last production release of BIND on the corresponding major release branch.

### 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.

### Security Fixes

- A specially crafted query could trigger an assertion failure in name.c.

  This flaw was discovered by Jonathan Foote, and is disclosed in CVE-2015-5477. [RT #39795]

- On servers configured to perform DNSSEC validation, an assertion failure could be triggered on answers from a specially configured server.

  This flaw was discovered by Breno Silveira Soares, and is disclosed in CVE-2015-4620. [RT #39795]

### New Features

- New quotas have been added to limit the queries that are sent by recursive resolvers to authoritative servers experiencing denial-of-service attacks. When configured, these options can both reduce the harm done to authoritative servers and also avoid the resource exhaustion that can be experienced by recursives when they are being used as a vehicle for such an attack.

  NOTE: These options are not available by default; use configure --enable-fetchlimit to include them in the build.

  - `fetches-per-server` limits the number of simultaneous queries that can be sent to any single authoritative server. The configured value is a starting point; it is automatically adjusted downward if the server is partially or completely non-responsive. The algorithm used to adjust the quota can be configured via the `fetch-quota-params` option.

  - `fetches-per-zone` limits the number of simultaneous queries that can be sent for names within a single domain. (Note: Unlike "fetches-per-server", this value is not self-tuning.)

  Statistics counters have also been added to track the number of queries affected by these quotas.

- An --enable-querytrace configure switch is now available to enable very verbose query tracelogging. This option can only be set at compile time. This option has a negative performance impact and should be used only for debugging.

- EDNS COOKIE options content is now displayed as "COOKIE: <hexvalue>".

### Feature Changes

- None

- Large inline-signing changes should be less disruptive. Signature generation is now done incrementally; the number of signatures to be generated in each quantum is controlled by "sig-signing-signatures `number`;". [RT #37927]

- Retrieving the local port range from net.ipv4.ip_local_port_range on Linux is now supported.

### Bug Fixes

- Asynchronous zone loads were not handled correctly when the zone load was already in progress; this could trigger a crash in zt.c. [RT #37573]

- A race during shutdown or reconfiguration could cause an assertion failure in mem.c. [RT #38979]

- Some answer formatting options didn't work correctly with dig +short. [RT #39291]

### End of Life

The BIND 9.9 (Extended Support Version) will be supported until June, 2017. 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/.