BIND 9 Contents 1. Introduction 2. Reporting bugs and getting help 3. Contributing to BIND 4. BIND 9.10 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 the 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/ bind9/releasenotes Reporting bugs and getting help Please report assertion failure errors and suspected security issues to security-officer@isc.org. General bug reports can be sent to bind9-bugs@isc.org. Feature requests can be sent to bind-suggest@isc.org. Please note that, while tickets submitted to ISC's ticketing system are not initially publicly readable by default, they can be made publicly acessible afterward. Please do not include information in bug reports that you consider to be confidential. In particular, when sending the contents of your configuration file, it is advisable to obscure key secrets: this can be done automatically by using named-checkconf -px. 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 either as Github pull requests or via email. When submitting a patch via email, please prepend the subject header with "[PATCH]" so it will be easier for us to find. If your patch introduces a new feature in BIND, please submit it to bind-suggest@isc.org ; if it fixes a bug, please submit it to bind9-bugs@isc.org. BIND 9.10 features BIND 9.10.0 includes a number of changes from BIND 9.9 and earlier releases. New features include: * DNS Response-rate limiting (DNS RRL), which blunts the impact of reflection and amplification attacks, is always compiled in and no longer requires a compile-time option to enable it. * An experimental "Source Identity Token" (SIT) EDNS option is now available. Similar to DNS Cookies as invented by Donald Eastlake 3rd, these are designed to enable clients to detect off-path spoofed responses, and to enable servers to detect spoofed-source queries. Servers can be configured to send smaller responses to clients that have not identified themselves using a SIT option, reducing the effectiveness of amplification attacks. RRL processing has also been updated; clients proven to be legitimate via SIT are not subject to rate limiting. Use configure --enable-sit to enable this feature in BIND. * A new zone file format, map, stores zone data in a format that can be mapped directly into memory, allowing significantly faster zone loading. * delv (domain entity lookup and validation) is a new tool with dig-like semantics for looking up DNS data and performing internal DNSSEC validation. This allows easy validation in environments where the resolver may not be trustworthy, and assists with troubleshooting of DNSSEC problems. (NOTE: In previous development releases of BIND 9.10, this utility was called delve. The spelling has been changed to avoid confusion with the delve utility included with the Xapian search engine.) * Improved EDNS(0) processing for better resolver performance and reliability over slow or lossy connections. * A new configure --with-tuning=large option tunes certain compiled-in constants and default settings to values better suited to large servers with abundant memory. This can improve performance on such servers, but will consume more memory and may degrade performance on smaller systems. * Substantial improvement in response-policy zone (RPZ) performance. Up to 32 response-policy zones can be configured with minimal performance loss. * To improve recursive resolver performance, cache records which are still being requested by clients can now be automatically refreshed from the authoritative server before they expire, reducing or eliminating the time window in which no answer is available in the cache. * New rpz-client-ip triggers and drop policies allowing response policies based on the IP address of the client. * ACLs can now be specified based on geographic location using the MaxMind GeoIP databases. Use configure --with-geoip to enable. * Zone data can now be shared between views, allowing multiple views to serve the same zones authoritatively without storing multiple copies in memory. * New XML schema (version 3) for the statistics channel includes many new statistics and uses a flattened XML tree for faster parsing. The older schema is now deprecated. * A new stylesheet, based on the Google Charts API, displays XML statistics in charts and graphs on javascript-enabled browsers. * The statistics channel can now provide data in JSON format as well as XML. * New stats counters track TCP and UDP queries received per zone, and EDNS options received in total. * The internal and export versions of the BIND libraries (libisc, libdns, etc) have been unified so that external library clients can use the same libraries as BIND itself. * A new compile-time option, configure --enable-native-pkcs11, allows BIND 9 cryptography functions to use the PKCS#11 API natively, so that BIND can drive a cryptographic hardware service module (HSM) directly instead of using a modified OpenSSL as an intermediary. (Note: This feature requires an HSM to have a full implementation of the PKCS#11 API; many current HSMs only have partial implementations. The new pkcs11-tokens command can be used to check API completeness. Native PKCS#11 is known to work with the Thales nShield HSM and with SoftHSM version 2 from the Open DNSSEC project.) * The new max-zone-ttl option enforces maximum TTLs for zones. This can simplify the process of rolling DNSSEC keys by guaranteeing that cached signatures will have expired within the specified amount of time. * dig +subnet sends an EDNS CLIENT-SUBNET option when querying. * dig +expire sends an EDNS EXPIRE option when querying. When this option is sent with an SOA query to a server that supports it, it will report the expiry time of a slave zone. * New dnssec-coverage tool to check DNSSEC key coverage for a zone and report if a lapse in signing coverage has been inadvertently scheduled. * Signing algorithm flexibility and other improvements for the rndc control channel. * named-checkzone and named-compilezone can now read journal files, allowing them to process dynamic zones. * Multiple DLZ databases can now be configured. Individual zones can be configured to be served from a specific DLZ database. DLZ databases now serve zones of type master and redirect. * rndc zonestatus reports information about a specified zone. * named now listens on IPv6 as well as IPv4 interfaces by default. * named now preserves the capitalization of names when responding to queries: for instance, a query for "example.com" may be answered with "example.COM" if the name was configured that way in the zone file. Some clients have a bug causing them to depend on the older behavior, in which the case of the answer always matched the case of the query, rather than the case of the name configured in the DNS. Such clients can now be specified in the new no-case-compress ACL; this will restore the older behavior of named for those clients only. * new dnssec-importkey command allows the use of offline DNSSEC keys with automatic DNSKEY management. * New named-rrchecker tool to verify the syntactic correctness of individual resource records. * When re-signing a zone, the new dnssec-signzone -Q option drops signatures from keys that are still published but are no longer active. * named-checkconf -px will print the contents of configuration files with the shared secrets obscured, making it easier to share configuration (e.g. when submitting a bug report) without revealing private information. * rndc scan causes named to re-scan network interfaces for changes in local addresses. * On operating systems with support for routing sockets, network interfaces are re-scanned automatically whenever they change. * tsig-keygen is now available as an alternate command name to use for ddns-confgen. BIND 9.10.1 BIND 9.10.1 is a maintenance release, and addresses the security flaws described in CVE-2014-3214 and CVE-2014-3859. BIND 9.10.2 BIND 9.10.2 is a maintenance release, and addresses the security flaws described in CVE-2014-8500, CVE-2014-8680 and CVE-2015-1349. BIND 9.10.3 BIND 9.10.3 is a maintenance release, and addresses the security flaws described in CVE-2015-4620, CVE-2015-5477, CVE-2015-5722, and CVE-2015-5986. It also makes the following new features available: * New "fetchlimit" quotas are now available 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. NOTE: These features are NOT built in by default; use configure --enable-fetchlimit to enable them. * dig now supports sending of arbitrary EDNS options by specifying them on the command line. BIND 9.10.4 BIND 9.10.4 is a maintenance release, and addresses the security flaws described in CVE-2015-8000, CVE-2015-8461, CVE-2015-8704, CVE-2015-8705, CVE-2016-1285, CVE-2016-1286, CVE-2016-2088, CVE-2016-2775 and CVE-2016-2776. BIND 9.10.5 BIND 9.10.5 is a maintenance release, and addresses the security flaws disclosed in CVE-2016-2775, CVE-2016-2776, CVE-2016-6170, CVE-2016-8864, CVE-2016-9131, CVE-2016-9147, CVE-2016-9444, CVE-2017-3135, CVE-2017-3136, CVE-2017-3137, and CVE-2017-3138. BIND 9.10.6 BIND 9.10.6 is a maintenance release, and addresses the security flaws disclosed in CVE-2017-3140 and CVE-2017-3141, CVE-2017-3142 and CVE-2017-3143. BIND 9.10.7 BIND 9.10.7 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=" 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=", 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 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". Portions of BIND that are written in Python, including dnssec-coverage, dnssec-checkds, and some of the system tests, require the 'argparse' module to be available. 'argparse' is a standard module as of Python 2.7 and Python 3.2. 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)