BIND 9

Contents

1. Introduction

2. Reporting bugs and getting help

3. Contributing to BIND

4. BIND 9.11 features

5. Building BIND

6. macOS

7. Compile-time options

8. Automated testing

9. Documentation

10. Change log

11. Acknowledgments

Introduction

BIND (Berkeley Internet Name Domain) is a complete, highly portable

implementation of the DNS (Domain Name System) protocol.

The BIND name server, named, is able to serve as an authoritative name

server, recursive resolver, DNS forwarder, or all three simultaneously. It

implements views for split-horizon DNS, automatic DNSSEC zone signing and

key management, catalog zones to facilitate provisioning of zone data

throughout a name server constellation, response policy zones (RPZ) to

protect clients from malicious data, response rate limiting (RRL) and

recursive query limits to reduce distributed denial of service attacks,

and many other advanced DNS features. BIND also includes a suite of

administrative tools, including the dig and delv DNS lookup tools,

nsupdate for dynamic DNS zone updates, rndc for remote name server

administration, and more.

BIND 9 is a complete re-write of the BIND architecture that was used in

versions 4 and 8. Internet Systems Consortium (https://www.isc.org), a 501

(c)(3) public benefit corporation dedicated to providing software and

services in support of the Internet infrastructure, developed BIND 9 and

is responsible for its ongoing maintenance and improvement. BIND is open

source software licenced under the terms of ISC License for all versions

up to and including BIND 9.10, and the Mozilla Public License version 2.0

for all subsequent verisons.

For a summary of features introduced in past major releases of BIND, see

the file HISTORY.

For a detailed list of changes made throughout the history of BIND 9, see

the file CHANGES. See below for details on the CHANGES file format.

For up-to-date release notes and errata, see http://www.isc.org/software/

Reporting bugs and getting help

To report non-security-sensitive bugs or request new features, you may

open an Issue in the BIND 9 project on the ISC GitLab server at https://

gitlab.isc.org/isc-projects/bind9.

Please note that, unless you explicitly mark the newly created Issue as

"confidential", it will be publicly readable. Please do not include any

information in bug reports that you consider to be confidential unless the

issue has been marked as such. In particular, if submitting the contents

of your configuration file in a non-confidential Issue, it is advisable to

obscure key secrets: this can be done automatically by using

named-checkconf -px.

If the bug you are reporting is a potential security issue, such as an

assertion failure or other crash in named, please do NOT use GitLab to

report it. Instead, please send mail to security-officer@isc.org.

Professional support and training for BIND are available from ISC at

https://www.isc.org/support.

To join the BIND Users mailing list, or view the archives, visit https://

lists.isc.org/mailman/listinfo/bind-users.

If you're planning on making changes to the BIND 9 source code, you may

also want to join the BIND Workers mailing list, at https://lists.isc.org/

mailman/listinfo/bind-workers.

Contributing to BIND

ISC maintains a public git repository for BIND; details can be found at

http://www.isc.org/git/, and also on Github at https://github.com/

isc-projects.

Information for BIND contributors can be found in the following files: -

General information: doc/dev/contrib.md - BIND 9 code style: doc/dev/

style.md - BIND architecture and developer guide: doc/dev/dev.md

Patches for BIND may be submitted as Merge Requests in the ISC GitLab

server at at https://gitlab.isc.org/isc-projects/bind9/merge_requests.

By default, external contributors don't have ability to fork BIND in the

GitLab server, but if you wish to contribute code to BIND, you may request

permission to do so. Thereafter, you can create git branches and directly

submit requests that they be reviewed and merged.

If you prefer, you may also submit code by opening a GitLab Issue and

including your patch as an attachment, preferably generated by git

format-patch.

BIND 9.11 features

BIND 9.11.0 includes a number of changes from BIND 9.10 and earlier

releases. New features include:

* Added support for Catalog Zones, a new method for provisioning

servers: a list of zones to be served is stored in a DNS zone, along

with their configuration parameters. Changes to the catalog zone are

propagated to slaves via normal AXFR/IXFR, whereupon the zones that

are listed in it are automatically added, deleted or reconfigured.

* Added support for "dnstap", a fast and flexible method of capturing

and logging DNS traffic.

* Added support for "dyndb", a new API for loading zone data from an

external database, developed by Red Hat for the FreeIPA project.

* "fetchlimit" quotas are now compiled in by default. These are for the

use of recursive resolvers that are are under high query load for

domains whose authoritative servers are nonresponsive or are

experiencing a denial of service attack:

+ 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.)

+ New stats counters have been added to count queries spilled due to

these quotas.

* Added a new dnssec-keymgr key mainenance utility, which can generate

or update keys as needed to ensure that a zone's keys match a defined

DNSSEC policy.

* The experimental "SIT" feature in BIND 9.10 has been renamed "COOKIE"

and is no longer optional. EDNS COOKIE is a mechanism enabling clients

to detect off-path spoofed responses, and servers to detect

spoofed-source queries. Clients that identify themselves using COOKIE

options are not subject to response rate limiting (RRL) and can

receive larger UDP responses.

* SERVFAIL responses can now be cached for a limited time (defaulting to

1 second, with an upper limit of 30). This can reduce the frequency of

retries when a query is persistently failing.

* Added an nsip-wait-recurse switch to RPZ. This causes NSIP rules to be

skipped if a name server IP address isn't in the cache yet; the

address will be looked up and the rule will be applied on future

queries.

* Added a Python RNDC module. This allows multiple commands to sent over

a persistent RNDC channel, which saves time.

* The controls block in named.conf can now grant read-only rndc access

to specified clients or keys. Read-only clients could, for example,

check rndc status but could not reconfigure or shut down the server.

* rndc commands can now return arbitrarily large amounts of text to the

caller.

* The zone serial number of a dynamically updatable zone can now be set

via rndc signing -serial <number> <zonename>. This allows

inline-signing zones to be set to a specific serial number.

* The new rndc nta command can be used to set a Negative Trust Anchor

(NTA), disabling DNSSEC validation for a specific domain; this can be

used when responses from a domain are known to be failing validation

due to administrative error rather than because of a spoofing attack.

Negative trust anchors are strictly temporary; by default they expire

after one hour, but can be configured to last up to one week.

* rndc delzone can now be used on zones that were not originally created

by "rndc addzone".

* rndc modzone reconfigures a single zone, without requiring the entire

server to be reconfigured.

* rndc showzone displays the current configuration of a zone.

* rndc managed-keys can be used to check the status of RFC 5001 managed

trust anchors, or to force trust anchors to be refreshed.

* max-cache-size can now be set to a percentage of available memory. The

default is 90%.

* Update forwarding performance has been improved by allowing a single

TCP connection to be shared by multiple updates.

* The EDNS Client Subnet (ECS) option is now supported for authoritative

servers; if a query contains an ECS option then ACLs containing geoip

or ecs elements can match against the the address encoded in the

option. This can be used to select a view for a query, so that

different answers can be provided depending on the client network.

* The EDNS EXPIRE option has been implemented on the client side,

allowing a slave server to set the expiration timer correctly when

transferring zone data from another slave server.

* The key generation and manipulation tools (dnssec-keygen,

dnssec-settime, dnssec-importkey, dnssec-keyfromlabel) now take -Psync

and -Dsync options to set the publication and deletion times of CDS

and CDNSKEY parent-synchronization records. Both named and

dnssec-signzone can now publish and remove these records at the

scheduled times.

* A new minimal-any option reduces the size of UDP responses for query

type ANY by returning a single arbitrarily selected RRset instead of

all RRsets.

* A new masterfile-style zone option controls the formatting of text

zone files: When set to full, a zone file is dumped in

single-line-per-record format.

* serial-update-method can now be set to date. On update, the serial

number will be set to the current date in YYYYMMDDNN format.

* dnssec-signzone -N date sets the serial number to YYYYMMDDNN.

* named -L <filename> causes named to send log messages to the specified

file by default instead of to the system log.

* dig +ttlunits prints TTL values with time-unit suffixes: w, d, h, m, s

for weeks, days, hours, minutes, and seconds.

* dig +unknownformat prints dig output in RFC 3597 "unknown record"

presentation format.

* dig +ednsopt allows dig to set arbitrary EDNS options on requests.

* dig +ednsflags allows dig to set yet-to-be-defined EDNS flags on

requests.

* mdig is an alternate version of dig which sends multiple pipelined TCP

queries to a server. Instead of waiting for a response after sending a

query, it sends all queries immediately and displays responses in the

order received.

* serial-query-rate no longer controls NOTIFY messages. These are

separately controlled by notify-rate and startup-notify-rate.

* nsupdate now performs check-names processing by default on records to

be added. This can be disabled with check-names no.

* The statistics channel now supports DEFLATE compression, reducing the

size of the data sent over the network when querying statistics.

* New counters have been added to the statistics channel to track the

sizes of incoming queries and outgoing responses in histogram buckets,

as specified in RSSAC002.

* A new NXDOMAIN redirect method (option nxdomain-redirect) has been

added, allowing redirection to a specified DNS namespace instead of a

single redirect zone.

* When starting up, named now ensures that no other named process is

already running.

* Files created by named to store information, including mkeys and nzf

files, are now named after their corresponding views unless the view

name contains characters incompatible with use as a filename. Old

style filenames (based on the hash of the view name) will still work.

BIND 9.11.1

BIND 9.11.1 is a maintenance release, and addresses the security flaws

disclosed in CVE-2016-6170, CVE-2016-8864, CVE-2016-9131, CVE-2016-9147,

CVE-2016-9444, CVE-2016-9778, CVE-2017-3135, CVE-2017-3136, CVE-2017-3137

and CVE-2017-3138.

BIND 9.11.2

BIND 9.11.2 is a maintenance release, and addresses the security flaws

disclosed in CVE-2017-3140, CVE-2017-3141, CVE-2017-3142 and

CVE-2017-3143. It also addresses several bugs related to the use of an

LMDB database to store data related to zones added via rndc addzone or

catalog zones.

BIND 9.11.3

BIND 9.11.3 is a maintenance release, and addresses the security flaw

disclosed in CVE-2017-3145.

Building BIND

BIND requires a UNIX or Linux system with an ANSI C compiler, basic POSIX

support, and a 64-bit integer type. Successful builds have been observed

on many versions of Linux and UNIX, including RedHat, Fedora, Debian,

Ubuntu, SuSE, Slackware, FreeBSD, NetBSD, OpenBSD, Mac OS X, Solaris,

HP-UX, AIX, SCO OpenServer, and OpenWRT.

BIND is also available for Windows XP, 2003, 2008, and higher. See

win32utils/readme1st.txt for details on building for Windows systems.

To build on a UNIX or Linux system, use:

$ ./configure

$ make

If you're planning on making changes to the BIND 9 source, you should run

make depend. If you're using Emacs, you might find make tags helpful.

Several environment variables that can be set before running configure

will affect compilation:

Variable Description

CC The C compiler to use. configure tries to figure out the

right one for supported systems.

C compiler flags. Defaults to include -g and/or -O2 as

CFLAGS supported by the compiler. Please include '-g' if you need

to set CFLAGS.

System header file directories. Can be used to specify

STD_CINCLUDES where add-on thread or IPv6 support is, for example.

Defaults to empty string.

Any additional preprocessor symbols you want defined.

STD_CDEFINES Defaults to empty string. For a list of possible settings,

see the file OPTIONS.

LDFLAGS Linker flags. Defaults to empty string.

BUILD_CC Needed when cross-compiling: the native C compiler to use

when building for the target system.

BUILD_CFLAGS Optional, used for cross-compiling

BUILD_CPPFLAGS

BUILD_LDFLAGS

BUILD_LIBS

macOS

Building on macOS assumes that the "Command Tools for Xcode" is installed.

This can be downloaded from https://developer.apple.com/download/more/ or

if you have Xcode already installed you can run "xcode-select --install".

This will add /usr/include to the system and install the compiler and

other tools so that they can be easily found.

Compile-time options

To see a full list of configuration options, run configure --help.

On most platforms, BIND 9 is built with multithreading support, allowing

it to take advantage of multiple CPUs. You can configure this by

specifying --enable-threads or --disable-threads on the configure command

line. The default is to enable threads, except on some older operating

systems on which threads are known to have had problems in the past.

(Note: Prior to BIND 9.10, the default was to disable threads on Linux

systems; this has now been reversed. On Linux systems, the threaded build

is known to change BIND's behavior with respect to file permissions; it

may be necessary to specify a user with the -u option when running named.)

To build shared libraries, specify --with-libtool on the configure command

line.

Certain compiled-in constants and default settings can be increased to

values better suited to large servers with abundant memory resources (e.g,

64-bit servers with 12G or more of memory) by specifying --with-tuning=

large on the configure command line. This can improve performance on big

servers, but will consume more memory and may degrade performance on

smaller systems.

For the server to support DNSSEC, you need to build it with crypto

support. To use OpenSSL, you should have OpenSSL 1.0.2e or newer

installed. If the OpenSSL library is installed in a nonstandard location,

specify the prefix using "--with-openssl=<PREFIX>" on the configure

command line. To use a PKCS#11 hardware service module for cryptographic

operations, specify the path to the PKCS#11 provider library using

"--with-pkcs11=<PREFIX>", and configure BIND with

"--enable-native-pkcs11".

To support the HTTP statistics channel, the server must be linked with at

least one of the following: libxml2 http://xmlsoft.org or json-c https://

github.com/json-c. If these are installed at a nonstandard location,

specify the prefix using --with-libxml2=/prefix or --with-libjson=/prefix.

To support compression on the HTTP statistics channel, the server must be

linked against libzlib. If this is installed in a nonstandard location,

specify the prefix using --with-zlib=/prefix.

To support storing configuration data for runtime-added zones in an LMDB

database, the server must be linked with liblmdb. If this is installed in

a nonstandard location, specify the prefix using "with-lmdb=/prefix".

To support GeoIP location-based ACLs, the server must be linked with

libGeoIP. This is not turned on by default; BIND must be configured with

"--with-geoip". If the library is installed in a nonstandard location, use

specify the prefix using "--with-geoip=/prefix".

For DNSTAP packet logging, you must have installed libfstrm https://

github.com/farsightsec/fstrm and libprotobuf-c https://

developers.google.com/protocol-buffers, and BIND must be configured with

"--enable-dnstap".

Portions of BIND that are written in Python, including dnssec-keymgr,

dnssec-coverage, dnssec-checkds, and some of the system tests, require the

'argparse' and 'ply' modules to be available. 'argparse' is a standard

module as of Python 2.7 and Python 3.2. 'ply' is available from https://

pypi.python.org/pypi/ply.

On some platforms it is necessary to explicitly request large file support

to handle files bigger than 2GB. This can be done by using

--enable-largefile on the configure command line.

Support for the "fixed" rrset-order option can be enabled or disabled by

specifying --enable-fixed-rrset or --disable-fixed-rrset on the configure

command line. By default, fixed rrset-order is disabled to reduce memory

footprint.

If your operating system has integrated support for IPv6, it will be used

automatically. If you have installed KAME IPv6 separately, use --with-kame

[=PATH] to specify its location.

make install will install named and the various BIND 9 libraries. By

default, installation is into /usr/local, but this can be changed with the

--prefix option when running configure.

You may specify the option --sysconfdir to set the directory where

configuration files like named.conf go by default, and --localstatedir to

set the default parent directory of run/named.pid. For backwards

compatibility with BIND 8, --sysconfdir defaults to /etc and

--localstatedir defaults to /var if no --prefix option is given. If there

is a --prefix option, sysconfdir defaults to $prefix/etc and localstatedir

defaults to $prefix/var.

Automated testing

A system test suite can be run with make test. The system tests require

you to configure a set of virtual IP addresses on your system (this allows

multiple servers to run locally and communicate with one another). These

IP addresses can be configured by running the command bin/tests/system/

ifconfig.sh up as root.

Some tests require Perl and the Net::DNS and/or IO::Socket::INET6 modules,

and will be skipped if these are not available. Some tests require Python

and the 'dnspython' module and will be skipped if these are not available.

See bin/tests/system/README for further details.

Unit tests are implemented using Automated Testing Framework (ATF). To run

them, use configure --with-atf, then run make test or make unit.

Documentation

The BIND 9 Administrator Reference Manual is included with the source

distribution, in DocBook XML, HTML and PDF format, in the doc/arm

directory.

Some of the programs in the BIND 9 distribution have man pages in their

directories. In particular, the command line options of named are

documented in bin/named/named.8.

Frequently (and not-so-frequently) asked questions and their answers can

be found in the ISC Knowledge Base at https://kb.isc.org.

Additional information on various subjects can be found in other README

files throughout the source tree.

Change log

A detailed list of all changes that have been made throughout the

development BIND 9 is included in the file CHANGES, with the most recent

changes listed first. Change notes include tags indicating the category of

the change that was made; these categories are:

Category Description

[func] New feature

[bug] General bug fix

[security] Fix for a significant security flaw

[experimental] Used for new features when the syntax or other aspects of

the design are still in flux and may change

[port] Portability enhancement

[maint] Updates to built-in data such as root server addresses and

keys

[tuning] Changes to built-in configuration defaults and constants to

improve performance

[performance] Other changes to improve server performance

[protocol] Updates to the DNS protocol such as new RR types

[test] Changes to the automatic tests, not affecting server

functionality

[cleanup] Minor corrections and refactoring

[doc] Documentation

[contrib] Changes to the contributed tools and libraries in the

'contrib' subdirectory

Used in the master development branch to reserve change

[placeholder] numbers for use in other branches, e.g. when fixing a bug

that only exists in older releases

In general, [func] and [experimental] tags will only appear in new-feature

releases (i.e., those with version numbers ending in zero). Some new

functionality may be backported to older releases on a case-by-case basis.

All other change types may be applied to all currently-supported releases.

Acknowledgments

* The original development of BIND 9 was underwritten by the following

organizations:

Sun Microsystems, Inc.

Hewlett Packard

Compaq Computer Corporation

IBM

Process Software Corporation

Silicon Graphics, Inc.

Network Associates, Inc.

U.S. Defense Information Systems Agency

USENIX Association

Stichting NLnet - NLnet Foundation

Nominum, Inc.

* This product includes software developed by the OpenSSL Project for

use in the OpenSSL Toolkit. http://www.OpenSSL.org/

* This product includes cryptographic software written by Eric Young

(eay@cryptsoft.com)

* This product includes software written by Tim Hudson

(tjh@cryptsoft.com)

# BIND 9

### Contents

1. [Introduction](#intro)

1. [Reporting bugs and getting help](#help)

1. [Contributing to BIND](#contrib)

1. [BIND 9.11 features](#features)

1. [Building BIND](#build)

1. [macOS](#macos)

1. [Compile-time options](#opts)

1. [Automated testing](#testing)

1. [Documentation](#doc)

1. [Change log](#changes)

1. [Acknowledgments](#ack)

### <a name="intro"/> Introduction

BIND (Berkeley Internet Name Domain) is a complete, highly portable

implementation of the DNS (Domain Name System) protocol.

The BIND name server, `named`, is able to serve as an authoritative name

server, recursive resolver, DNS forwarder, or all three simultaneously. It

implements views for split-horizon DNS, automatic DNSSEC zone signing and

key management, catalog zones to facilitate provisioning of zone data

throughout a name server constellation, response policy zones (RPZ) to

protect clients from malicious data, response rate limiting (RRL) and

recursive query limits to reduce distributed denial of service attacks,

and many other advanced DNS features. BIND also includes a suite of

administrative tools, including the `dig` and `delv` DNS lookup tools,

`nsupdate` for dynamic DNS zone updates, `rndc` for remote name server

administration, and more.

BIND 9 is a complete re-write of the BIND architecture that was used in

versions 4 and 8. Internet Systems Consortium

([https://www.isc.org](https://www.isc.org)), a 501(c)(3) public benefit

corporation dedicated to providing software and services in support of the

Internet infrastructure, developed BIND 9 and is responsible for its

ongoing maintenance and improvement. BIND is open source software

licenced under the terms of ISC License for all versions up to and

including BIND 9.10, and the Mozilla Public License version 2.0 for all

subsequent verisons.

For a summary of features introduced in past major releases of BIND,

see the file [HISTORY](HISTORY.md).

For a detailed list of changes made throughout the history of BIND 9, see

the file [CHANGES](CHANGES). See [below](#changes) for details on the

CHANGES file format.

For up-to-date release notes and errata, see

[http://www.isc.org/software/bind9/releasenotes](http://www.isc.org/software/bind9/releasenotes)

### <a name="help"/> Reporting bugs and getting help

To report non-security-sensitive bugs or request new features, you may

open an Issue in the BIND 9 project on the

[ISC GitLab server](https://gitlab.isc.org) at

[https://gitlab.isc.org/isc-projects/bind9](https://gitlab.isc.org/isc-projects/bind9).

Please note that, unless you explicitly mark the newly created Issue as

"confidential", it will be publicly readable. Please do not include any

information in bug reports that you consider to be confidential unless

the issue has been marked as such. In particular, if submitting the

contents of your configuration file in a non-confidential Issue, it is

advisable to obscure key secrets: this can be done automatically by

using `named-checkconf -px`.

If the bug you are reporting is a potential security issue, such as an

assertion failure or other crash in `named`, please do *NOT* use GitLab to

report it. Instead, please send mail to

[security-officer@isc.org](mailto:security-officer@isc.org).

Professional support and training for BIND are available from

ISC at [https://www.isc.org/support](https://www.isc.org/support).

To join the __BIND Users__ mailing list, or view the archives, visit

[https://lists.isc.org/mailman/listinfo/bind-users](https://lists.isc.org/mailman/listinfo/bind-users).

If you're planning on making changes to the BIND 9 source code, you

may also want to join the __BIND Workers__ mailing list, at

[https://lists.isc.org/mailman/listinfo/bind-workers](https://lists.isc.org/mailman/listinfo/bind-workers).

### <a name="contrib"/> Contributing to BIND

ISC maintains a public git repository for BIND; details can be found

at [http://www.isc.org/git/](http://www.isc.org/git/), and also on Github

at [https://github.com/isc-projects](https://github.com/isc-projects).

Information for BIND contributors can be found in the following files:

- General information: [doc/dev/contrib.md](doc/dev/contrib.md)

- BIND 9 code style: [doc/dev/style.md](doc/dev/style.md)

- BIND architecture and developer guide: [doc/dev/dev.md](doc/dev/dev.md)

Patches for BIND may be submitted as

[Merge Requests](https://gitlab.isc.org/isc-projects/bind9/merge_requests)

in the [ISC GitLab server](https://gitlab.isc.org) at

at [https://gitlab.isc.org/isc-projects/bind9/merge_requests](https://gitlab.isc.org/isc-projects/bind9/merge_requests).

By default, external contributors don't have ability to fork BIND in the

GitLab server, but if you wish to contribute code to BIND, you may request

permission to do so. Thereafter, you can create git branches and directly

submit requests that they be reviewed and merged.

If you prefer, you may also submit code by opening a

[GitLab Issue](https://gitlab.isc.org/isc-projects/bind9/issues) and

including your patch as an attachment, preferably generated by

`git format-patch`.

### <a name="features"/> BIND 9.11 features

BIND 9.11.0 includes a number of changes from BIND 9.10 and earlier

releases. New features include:

* Added support for Catalog Zones, a new method for provisioning servers: a

list of zones to be served is stored in a DNS zone, along with their

configuration parameters. Changes to the catalog zone are propagated to

slaves via normal AXFR/IXFR, whereupon the zones that are listed in it

are automatically added, deleted or reconfigured.

* Added support for "dnstap", a fast and flexible method of capturing and

logging DNS traffic.

* Added support for "dyndb", a new API for loading zone data from an

external database, developed by Red Hat for the FreeIPA project.

* "fetchlimit" quotas are now compiled in by default. These are for the

use of recursive resolvers that are are under high query load for domains

whose authoritative servers are nonresponsive or are experiencing a

denial of service attack:

* `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.)

* New stats counters have been added to count queries spilled due to

these quotas.

* Added a new `dnssec-keymgr` key mainenance utility, which can generate or

update keys as needed to ensure that a zone's keys match a defined DNSSEC

policy.

* The experimental "SIT" feature in BIND 9.10 has been renamed "COOKIE" and

is no longer optional. EDNS COOKIE is a mechanism enabling clients to

detect off-path spoofed responses, and servers to detect spoofed-source

queries. Clients that identify themselves using COOKIE options are not

subject to response rate limiting (RRL) and can receive larger UDP

responses.

* SERVFAIL responses can now be cached for a limited time (defaulting to 1

second, with an upper limit of 30). This can reduce the frequency of

retries when a query is persistently failing.

* Added an `nsip-wait-recurse` switch to RPZ. This causes NSIP rules to be

skipped if a name server IP address isn't in the cache yet; the address

will be looked up and the rule will be applied on future queries.

* Added a Python RNDC module. This allows multiple commands to sent over a

persistent RNDC channel, which saves time.

* The `controls` block in named.conf can now grant read-only `rndc` access

to specified clients or keys. Read-only clients could, for example, check

`rndc status` but could not reconfigure or shut down the server.

* `rndc` commands can now return arbitrarily large amounts of text to the

caller.

* The zone serial number of a dynamically updatable zone can now be set via

`rndc signing -serial <number> <zonename>`. This allows inline-signing

zones to be set to a specific serial number.

* The new `rndc nta` command can be used to set a Negative Trust Anchor

(NTA), disabling DNSSEC validation for a specific domain; this can be

used when responses from a domain are known to be failing validation due

to administrative error rather than because of a spoofing attack.

Negative trust anchors are strictly temporary; by default they expire

after one hour, but can be configured to last up to one week.

* `rndc delzone` can now be used on zones that were not originally created

by "rndc addzone".

* `rndc modzone` reconfigures a single zone, without requiring the entire

server to be reconfigured.

* `rndc showzone` displays the current configuration of a zone.

* `rndc managed-keys` can be used to check the status of RFC 5001 managed

trust anchors, or to force trust anchors to be refreshed.

* `max-cache-size` can now be set to a percentage of available memory. The

default is 90%.

* Update forwarding performance has been improved by allowing a single TCP

connection to be shared by multiple updates.

* The EDNS Client Subnet (ECS) option is now supported for authoritative

servers; if a query contains an ECS option then ACLs containing `geoip`

or `ecs` elements can match against the the address encoded in the

option. This can be used to select a view for a query, so that different

answers can be provided depending on the client network.

* The EDNS EXPIRE option has been implemented on the client side, allowing

a slave server to set the expiration timer correctly when transferring

zone data from another slave server.

* The key generation and manipulation tools (`dnssec-keygen`,

`dnssec-settime`, `dnssec-importkey`, `dnssec-keyfromlabel`) now take

`-Psync` and `-Dsync` options to set the publication and deletion times

of CDS and CDNSKEY parent-synchronization records. Both `named` and

`dnssec-signzone` can now publish and remove these records at the

scheduled times.

* A new `minimal-any` option reduces the size of UDP responses for query

type ANY by returning a single arbitrarily selected RRset instead of all

RRsets.

* A new `masterfile-style` zone option controls the formatting of text zone

files: When set to `full`, a zone file is dumped in

single-line-per-record format.

* `serial-update-method` can now be set to `date`. On update, the serial

number will be set to the current date in YYYYMMDDNN format.

* `dnssec-signzone -N date` sets the serial number to YYYYMMDDNN.

* `named -L <filename>` causes named to send log messages to the specified

file by default instead of to the system log.

* `dig +ttlunits` prints TTL values with time-unit suffixes: w, d, h, m, s

for weeks, days, hours, minutes, and seconds.

* `dig +unknownformat` prints dig output in RFC 3597 "unknown record"

presentation format.

* `dig +ednsopt` allows dig to set arbitrary EDNS options on requests.

* `dig +ednsflags` allows dig to set yet-to-be-defined EDNS flags on

requests.

* `mdig` is an alternate version of dig which sends multiple pipelined TCP

queries to a server. Instead of waiting for a response after sending a

query, it sends all queries immediately and displays responses in the

order received.

* `serial-query-rate` no longer controls NOTIFY messages. These are

separately controlled by `notify-rate` and `startup-notify-rate`.

* `nsupdate` now performs `check-names` processing by default on records to

be added. This can be disabled with `check-names no`.

* The statistics channel now supports DEFLATE compression, reducing the

size of the data sent over the network when querying statistics.

* New counters have been added to the statistics channel to track the sizes

of incoming queries and outgoing responses in histogram buckets, as

specified in RSSAC002.

* A new NXDOMAIN redirect method (option `nxdomain-redirect`) has been

added, allowing redirection to a specified DNS namespace instead of a

single redirect zone.

* When starting up, named now ensures that no other named process is

already running.

* Files created by named to store information, including `mkeys` and `nzf`

files, are now named after their corresponding views unless the view name

contains characters incompatible with use as a filename. Old style

filenames (based on the hash of the view name) will still work.

#### BIND 9.11.1

BIND 9.11.1 is a maintenance release, and addresses the security

flaws disclosed in CVE-2016-6170, CVE-2016-8864, CVE-2016-9131,

CVE-2016-9147, CVE-2016-9444, CVE-2016-9778, CVE-2017-3135,

CVE-2017-3136, CVE-2017-3137 and CVE-2017-3138.

#### BIND 9.11.2

BIND 9.11.2 is a maintenance release, and addresses the security flaws

disclosed in CVE-2017-3140, CVE-2017-3141, CVE-2017-3142 and CVE-2017-3143.

It also addresses several bugs related to the use of an LMDB database to

store data related to zones added via `rndc addzone` or catalog zones.

#### BIND 9.11.3

BIND 9.11.3 is a maintenance release, and addresses the security flaw

disclosed in CVE-2017-3145.

### <a name="build"/> Building BIND

BIND requires a UNIX or Linux system with an ANSI C compiler, basic POSIX

support, and a 64-bit integer type. Successful builds have been observed on

many versions of Linux and UNIX, including RedHat, Fedora, Debian, Ubuntu,

SuSE, Slackware, FreeBSD, NetBSD, OpenBSD, Mac OS X, Solaris, HP-UX, AIX,

SCO OpenServer, and OpenWRT.

BIND is also available for Windows XP, 2003, 2008, and higher. See

`win32utils/readme1st.txt` for details on building for Windows systems.

To build on a UNIX or Linux system, use:

$ /configure

$ make

If you're planning on making changes to the BIND 9 source, you should run

`make depend`. If you're using Emacs, you might find `make tags` helpful.

Several environment variables that can be set before running `configure` will

affect compilation:

|Variable|Description |

|--------------------|-----------------------------------------------|

|`CC`|The C compiler to use. `configure` tries to figure out the right one for supported systems.|

|`CFLAGS`|C compiler flags. Defaults to include -g and/or -O2 as supported by the compiler. Please include '-g' if you need to set `CFLAGS`. |

|`STD_CINCLUDES`|System header file directories. Can be used to specify where add-on thread or IPv6 support is, for example. Defaults to empty string.|

|`STD_CDEFINES`|Any additional preprocessor symbols you want defined. Defaults to empty string. For a list of possible settings, see the file [OPTIONS](OPTIONS.md).|

|`LDFLAGS`|Linker flags. Defaults to empty string.|

|`BUILD_CC`|Needed when cross-compiling: the native C compiler to use when building for the target system.|

|`BUILD_CFLAGS`|Optional, used for cross-compiling|

|`BUILD_CPPFLAGS`||

|`BUILD_LDFLAGS`||

|`BUILD_LIBS`||

#### <a name="macos"> macOS

Building on macOS assumes that the "Command Tools for Xcode" is installed.

This can be downloaded from https://developer.apple.com/download/more/

or if you have Xcode already installed you can run "xcode-select --install".

This will add /usr/include to the system and install the compiler and other

tools so that they can be easily found.

#### <a name="opts"/> Compile-time options

To see a full list of configuration options, run `configure --help`.

On most platforms, BIND 9 is built with multithreading support, allowing it

to take advantage of multiple CPUs. You can configure this by specifying

`--enable-threads` or `--disable-threads` on the `configure` command line.

The default is to enable threads, except on some older operating systems on

which threads are known to have had problems in the past. (Note: Prior to

BIND 9.10, the default was to disable threads on Linux systems; this has

now been reversed. On Linux systems, the threaded build is known to change

BIND's behavior with respect to file permissions; it may be necessary to

specify a user with the -u option when running `named`.)

To build shared libraries, specify `--with-libtool` on the `configure`

command line.

Certain compiled-in constants and default settings can be increased to

values better suited to large servers with abundant memory resources (e.g,

64-bit servers with 12G or more of memory) by specifying

`--with-tuning=large` on the `configure` command line. This can improve

performance on big servers, but will consume more memory and may degrade

performance on smaller systems.

For the server to support DNSSEC, you need to build it with crypto support.

To use OpenSSL, you should have OpenSSL 1.0.2e or newer installed. If the

OpenSSL library is installed in a nonstandard location, specify the prefix

using "--with-openssl=&lt;PREFIX&gt;" on the configure command line. To use a

PKCS#11 hardware service module for cryptographic operations, specify the

path to the PKCS#11 provider library using "--with-pkcs11=&lt;PREFIX&gt;", and

configure BIND with "--enable-native-pkcs11".

To support the HTTP statistics channel, the server must be linked with at

least one of the following: libxml2

[http://xmlsoft.org](http://xmlsoft.org) or json-c

[https://github.com/json-c](https://github.com/json-c). If these are

installed at a nonstandard location, specify the prefix using

`--with-libxml2=/prefix` or `--with-libjson=/prefix`.

To support compression on the HTTP statistics channel, the server must be

linked against libzlib. If this is installed in a nonstandard location,

specify the prefix using `--with-zlib=/prefix`.

To support storing configuration data for runtime-added zones in an LMDB

database, the server must be linked with liblmdb. If this is installed in a

nonstandard location, specify the prefix using "with-lmdb=/prefix".

To support GeoIP location-based ACLs, the server must be linked with

libGeoIP. This is not turned on by default; BIND must be configured with

"--with-geoip". If the library is installed in a nonstandard location, use

specify the prefix using "--with-geoip=/prefix".

For DNSTAP packet logging, you must have installed libfstrm

[https://github.com/farsightsec/fstrm](https://github.com/farsightsec/fstrm)

and libprotobuf-c

[https://developers.google.com/protocol-buffers](https://developers.google.com/protocol-buffers),

and BIND must be configured with "--enable-dnstap".

Portions of BIND that are written in Python, including

`dnssec-keymgr`, `dnssec-coverage`, `dnssec-checkds`, and some of the

system tests, require the 'argparse' and 'ply' modules to be available.

'argparse' is a standard module as of Python 2.7 and Python 3.2.

'ply' is available from [https://pypi.python.org/pypi/ply](https://pypi.python.org/pypi/ply).

On some platforms it is necessary to explicitly request large file support

to handle files bigger than 2GB. This can be done by using

`--enable-largefile` on the `configure` command line.

Support for the "fixed" rrset-order option can be enabled or disabled by

specifying `--enable-fixed-rrset` or `--disable-fixed-rrset` on the

configure command line. By default, fixed rrset-order is disabled to

reduce memory footprint.

If your operating system has integrated support for IPv6, it will be used

automatically. If you have installed KAME IPv6 separately, use

`--with-kame[=PATH]` to specify its location.

`make install` will install `named` and the various BIND 9 libraries. By

default, installation is into /usr/local, but this can be changed with the

`--prefix` option when running `configure`.

You may specify the option `--sysconfdir` to set the directory where

configuration files like `named.conf` go by default, and `--localstatedir`

to set the default parent directory of `run/named.pid`. For backwards

compatibility with BIND 8, `--sysconfdir` defaults to `/etc` and

`--localstatedir` defaults to `/var` if no `--prefix` option is given. If

there is a `--prefix` option, sysconfdir defaults to `$prefix/etc` and

localstatedir defaults to `$prefix/var`.

### <a name="testing"/> Automated testing

A system test suite can be run with `make test`. The system tests require

you to configure a set of virtual IP addresses on your system (this allows

multiple servers to run locally and communicate with one another). These

IP addresses can be configured by running the command

`bin/tests/system/ifconfig.sh up` as root.

Some tests require Perl and the Net::DNS and/or IO::Socket::INET6 modules,

and will be skipped if these are not available. Some tests require Python

and the 'dnspython' module and will be skipped if these are not available.

See bin/tests/system/README for further details.

Unit tests are implemented using Automated Testing Framework (ATF).

To run them, use `configure --with-atf`, then run `make test` or

`make unit`.

### <a name="doc"/> Documentation

The *BIND 9 Administrator Reference Manual* is included with the source

distribution, in DocBook XML, HTML and PDF format, in the `doc/arm`

directory.

Some of the programs in the BIND 9 distribution have man pages in their

directories. In particular, the command line options of `named` are

documented in `bin/named/named.8`.

Frequently (and not-so-frequently) asked questions and their answers

can be found in the ISC Knowledge Base at

[https://kb.isc.org](https://kb.isc.org).

Additional information on various subjects can be found in other

`README` files throughout the source tree.

### <a name="changes"/> Change log

A detailed list of all changes that have been made throughout the

development BIND 9 is included in the file CHANGES, with the most recent

changes listed first. Change notes include tags indicating the category of

the change that was made; these categories are:

|Category |Description |

|-------------- |-----------------------------------------------|

| [func] | New feature |

| [bug] | General bug fix |

| [security] | Fix for a significant security flaw |

| [experimental] | Used for new features when the syntax or other aspects of the design are still in flux and may change |

| [port] | Portability enhancement |

| [maint] | Updates to built-in data such as root server addresses and keys |

| [tuning] | Changes to built-in configuration defaults and constants to improve performance |

| [performance] | Other changes to improve server performance |

| [protocol] | Updates to the DNS protocol such as new RR types |

| [test] | Changes to the automatic tests, not affecting server functionality |

| [cleanup] | Minor corrections and refactoring |

| [doc] | Documentation |

| [contrib] | Changes to the contributed tools and libraries in the 'contrib' subdirectory |

| [placeholder] | Used in the master development branch to reserve change numbers for use in other branches, e.g. when fixing a bug that only exists in older releases |

In general, [func] and [experimental] tags will only appear in new-feature

releases (i.e., those with version numbers ending in zero). Some new

functionality may be backported to older releases on a case-by-case basis.

All other change types may be applied to all currently-supported releases.

### <a name="ack"/> Acknowledgments

* The original development of BIND 9 was underwritten by the

following organizations:

Sun Microsystems, Inc.

Hewlett Packard

Compaq Computer Corporation

IBM

Process Software Corporation

Silicon Graphics, Inc.

Network Associates, Inc.

U.S. Defense Information Systems Agency

USENIX Association

Stichting NLnet - NLnet Foundation

Nominum, Inc.

* This product includes software developed by the OpenSSL Project for use

in the OpenSSL Toolkit.

[http://www.OpenSSL.org/](http://www.OpenSSL.org/)

* This product includes cryptographic software written by Eric Young

(eay@cryptsoft.com)

* This product includes software written by Tim Hudson (tjh@cryptsoft.com)