Release Notes for BIND Version 9.14.0

Introduction

BIND 9.14.0 is the first release of a new stable branch of BIND. This
document summarizes new features and functional changes that have been
introduced, as well as features that have been deprecated or removed,
since the last stable branch, 9.12.

Please see the file CHANGES for a more detailed list of changes and bug
fixes.

Note on Version Numbering

As of BIND 9.13/9.14, BIND has adopted the "odd-unstable/even-stable"
release numbering convention. BIND 9.14 contains new features added during
the BIND 9.13 development process. Henceforth, the 9.14 branch will be
limited to bug fixes and new feature development will proceed in the
unstable 9.15 branch, and so forth.

Supported Platforms

Since 9.12, BIND has undergone substantial code refactoring and cleanup,
and some very old code has been removed that was needed to support legacy
platforms which are no longer supported by their vendors and for which ISC
is no longer able to perform quality assurance testing. Specifically,
workarounds for old versions of UnixWare, BSD/OS, AIX, Tru64, SunOS,
TruCluster and IRIX have been removed.

On UNIX-like systems, BIND now requires support for POSIX.1c threads (IEEE
Std 1003.1c-1995), the Advanced Sockets API for IPv6 (RFC 3542), and
standard atomic operations provided by the C compiler.

More information can be found in the PLATFORM.md file that is included in
the source distribution of BIND 9. If your platform compiler and system
libraries provide the above features, BIND 9 should compile and run. If
that isn't the case, the BIND development team will generally accept
patches that add support for systems that are still supported by their
respective vendors.

As of BIND 9.14, the BIND development team has also made cryptography
(i.e., TSIG and DNSSEC) an integral part of the DNS server. The OpenSSL
cryptography library must be available for the target platform. A PKCS#11
provider can be used instead for Public Key cryptography (i.e., DNSSEC
signing and validation), but OpenSSL is still required for general
cryptography operations such as hashing and random number generation.

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.

Known Issues

  * A recent change in the named.conf parser resulted in allow-update
    being treated as a configuration error when set at the options or view
    level. This is not a secure configuration and the use of the option in
    this manner is ill-advised. However, in this release it should have
    been treated as a warning rather than a fatal error. This flaw was
    discovered too late to be fixed in 9.14.0, but it will be corrected in
    the 9.14.1 maintenance release: global allow-update will again be
    permitted, but a warning will be logged.

New Features

  * Task manager and socket code have been substantially modified. The
    manager uses per-cpu queues for tasks and network stack runs multiple
    event loops in CPU-affinitive threads. This greatly improves
    performance on large systems, especially when using multi-queue NICs.

  * Support for QNAME minimization was added and enabled by default in
    relaxed mode, in which BIND will fall back to normal resolution if the
    remote server returns something unexpected during the query
    minimization process. This default setting might change to strict in
    the future.

  * A new plugin mechanism has been added to allow extension of query
    processing functionality through the use of external libraries. The
    new filter-aaaa.so plugin replaces the filter-aaaa feature that was
    formerly implemented as a native part of BIND.

    The plugin API is a work in progress and is likely to evolve as
    further plugins are implemented. [GL #15]

  * A new secondary zone option, mirror, enables named to serve a
    transferred copy of a zone's contents without acting as an authority
    for the zone. A zone must be fully validated against an active trust
    anchor before it can be used as a mirror zone. DNS responses from
    mirror zones do not set the AA bit ("authoritative answer"), but do
    set the AD bit ("authenticated data"). This feature is meant to
    facilitate deployment of a local copy of the root zone, as described
    in RFC 7706. [GL #33]

  * BIND now can be compiled against the libidn2 library to add IDNA2008
    support. Previously, BIND supported IDNA2003 using the (now obsolete
    and unsupported) idnkit-1 library.

  * named now supports the "root key sentinel" mechanism. This enables
    validating resolvers to indicate which trust anchors are configured
    for the root, so that information about root key rollover status can
    be gathered. To disable this feature, add root-key-sentinel no; to
    named.conf. [GL #37]

  * The dnskey-sig-validity option allows the sig-validity-interval to be
    overriden for signatures covering DNSKEY RRsets. [GL #145]

  * When built on Linux, BIND now requires the libcap library to set
    process privileges. The adds a new compile-time dependency, which can
    be met on most Linux platforms by installing the libcap-dev or
    libcap-devel package. BIND can also be built without capability
    support by using configure --disable-linux-caps, at the cost of some
    loss of security.

  * The validate-except option specifies a list of domains beneath which
    DNSSEC validation should not be performed, regardless of whether a
    trust anchor has been configured above them. [GL #237]

  * Two new update policy rule types have been added krb5-selfsub and
    ms-selfsub which allow machines with Kerberos principals to update the
    name space at or below the machine names identified in the respective
    principals.

  * The new configure option --enable-fips-mode can be used to make BIND
    enable and enforce FIPS mode in the OpenSSL library. When compiled
    with such option the BIND will refuse to run if FIPS mode can't be
    enabled, thus this option must be only enabled for the systems where
    FIPS mode is available.

  * Two new configuration options min-cache-ttl and min-ncache-ttl has
    been added to allow the BIND 9 administrator to override the minimum
    TTL in the received DNS records (positive caching) and for storing the
    information about non-existent records (negative caching). The
    configured minimum TTL for both configuration options cannot exceed 90
    seconds.

  * rndc status output now includes a reconfig/reload in progress status
    line if named configuration is being reloaded.

  * The new answer-cookie option, if set to no, prevents named from
    returning a DNS COOKIE option to a client, even if such an option was
    present in the request. This is only intended as a temporary measure,
    for use when named shares an IP address with other servers that do not
    yet support DNS COOKIE. A mismatch between servers on the same address
    is not expected to cause operational problems, but the option to
    disable COOKIE responses so that all servers have the same behavior is
    provided out of an abundance of caution. DNS COOKIE is an important
    security mechanism, and this option should not be used to disable it
    unless absolutely necessary.

Removed Features

  * Workarounds for servers that misbehave when queried with EDNS have
    been removed, because these broken servers and the workarounds for
    their noncompliance cause unnecessary delays, increase code
    complexity, and prevent deployment of new DNS features. See https://
    dnsflagday.net for further details.

    In particular, resolution will no longer fall back to plain DNS when
    there was no response from an authoritative server. This will cause
    some domains to become non-resolvable without manual intervention. In
    these cases, resolution can be restored by adding server clauses for
    the offending servers, specifying edns no or send-cookie no, depending
    on the specific noncompliance.

    To determine which server clause to use, run the following commands to
    send queries to the authoritative servers for the broken domain:


      dig soa <zone> @<server> +dnssec
      dig soa <zone> @<server> +dnssec +nocookie
      dig soa <zone> @<server> +noedns

    If the first command fails but the second succeeds, the server most
    likely needs send-cookie no. If the first two fail but the third
    succeeds, then the server needs EDNS to be fully disabled with edns no
    .

    Please contact the administrators of noncompliant domains and
    encourage them to upgrade their broken DNS servers. [GL #150]

  * Previously, it was possible to build BIND without thread support for
    old architectures and systems without threads support. BIND now
    requires threading support (either POSIX or Windows) from the
    operating system, and it cannot be built without threads.

  * The filter-aaaa, filter-aaaa-on-v4, and filter-aaaa-on-v6 options have
    been removed from named, and can no longer be configured using native
    named.conf syntax. However, loading the new filter-aaaa.so plugin and
    setting its parameters provides identical functionality.

  * named can no longer use the EDNS CLIENT-SUBNET option for view
    selection. In its existing form, the authoritative ECS feature was not
    fully RFC-compliant, and could not realistically have been deployed in
    production for an authoritative server; its only practical use was for
    testing and experimentation. In the interest of code simplification,
    this feature has now been removed.

    The ECS option is still supported in dig and mdig via the +subnet
    argument, and can be parsed and logged when received by named, but it
    is no longer used for ACL processing. The geoip-use-ecs option is now
    obsolete; a warning will be logged if it is used in named.conf. ecs
    tags in an ACL definition are also obsolete, and will cause the
    configuration to fail to load if they are used. [GL #32]

  * dnssec-keygen can no longer generate HMAC keys for TSIG
    authentication. Use tsig-keygen to generate these keys. [RT #46404]

  * Support for OpenSSL 0.9.x has been removed. OpenSSL version 1.0.0 or
    greater, or LibreSSL is now required.

  * The configure --enable-seccomp option, which formerly turned on
    system-call filtering on Linux, has been removed. [GL #93]

  * IPv4 addresses in forms other than dotted-quad are no longer accepted
    in master files. [GL #13] [GL #56]

  * IDNA2003 support via (bundled) idnkit-1.0 has been removed.

  * The "rbtdb64" database implementation (a parallel implementation of
    "rbt") has been removed. [GL #217]

  * The -r randomdev option to explicitly select random device has been
    removed from the ddns-confgen, rndc-confgen, nsupdate, dnssec-confgen,
    and dnssec-signzone commands.

    The -p option to use pseudo-random data has been removed from the
    dnssec-signzone command.

  * Support for the RSAMD5 algorithm has been removed freom BIND as the
    usage of the RSAMD5 algorithm for DNSSEC has been deprecated in
    RFC6725, the security of the MD5 algorithm has been compromised, and
    its usage is considered harmful.

  * Support for the ECC-GOST (GOST R 34.11-94) algorithm has been removed
    from BIND, as the algorithm has been superseded by GOST R 34.11-2012
    in RFC6986 and it must not be used in new deployments. BIND will
    neither create new DNSSEC keys, signatures and digests, nor it will
    validate them.

  * Support for DSA and DSA-NSEC3-SHA1 algorithms has been removed from
    BIND as the DSA key length is limited to 1024 bits and this is not
    considered secure enough.

  * named will no longer ignore "no-change" deltas when processing an IXFR
    stream. This had previously been permitted for compatibility with BIND
    8, but now "no-change" deltas will trigger a fallback to AXFR as the
    recovery mechanism.

  * BIND 9 will no longer build on platforms that don't have proper IPv6
    support. BIND 9 now also requires POSIX-compatible pthread support.
    Most of the platforms that lack these featuers are long past their
    end-of-lifew dates, and they are neither developed nor supported by
    their respective vendors.

  * The incomplete support for internationalization message catalogs has
    been removed from BIND. Since the internationalization was never
    completed, and no localized message catalogs were ever made available
    for the portions of BIND in which they could have been used, this
    change will have no effect except to simplify the source code. BIND's
    log messages and other output were already only available in English.

Feature Changes

  * BIND will now always use the best CSPRNG (cryptographically-secure
    pseudo-random number generator) available on the platform where it is
    compiled. It will use the arc4random() family of functions on BSD
    operating systems, getrandom() on Linux and Solaris, CryptGenRandom on
    Windows, and the selected cryptography provider library (OpenSSL or
    PKCS#11) as the last resort. [GL #221]

  * The default setting for dnssec-validation is now auto, which activates
    DNSSEC validation using the IANA root key. (The default can be changed
    back to yes, which activates DNSSEC validation only when keys are
    explicitly configured in named.conf, by building BIND with configure
    --disable-auto-validation.) [GL #30]

  * BIND can no longer be built without DNSSEC support. A cryptography
    provider (i.e., OpenSSL or a hardware service module with PKCS#11
    support) must be available. [GL #244]

  * Zone types primary and secondary are now available as synonyms for
    master and slave, respectively, in named.conf.

  * named will now log a warning if the old root DNSSEC key is explicitly
    configured and has not been updated. [RT #43670]

  * dig +nssearch will now list name servers that have timed out, in
    addition to those that respond. [GL #64]

  * Up to 64 response-policy zones are now supported by default;
    previously the limit was 32. [GL #123]

  * Several configuration options for time periods can now use TTL value
    suffixes (for example, 2h or 1d) in addition to an integer number of
    seconds. These include fstrm-set-reopen-interval, interface-interval,
    max-cache-ttl, max-ncache-ttl, max-policy-ttl, and min-update-interval
    . [GL #203]

  * NSID logging (enabled by the request-nsid option) now has its own nsid
    category, instead of using the resolver category.

  * The rndc nta command could not differentiate between views of the same
    name but different class; this has been corrected with the addition of
    a -class option. [GL #105]

  * allow-recursion-on and allow-query-cache-on each now default to the
    other if only one of them is set, in order to be consistent with the
    way allow-recursion and allow-query-cache work. [GL #319]

  * When compiled with IDN support, the dig and nslookup commands now
    disable IDN processing when the standard output is not a TTY (i.e.,
    when the output is not being read by a human). When running from a
    shell script, the command line options +idnin and +idnout may be used
    to enable IDN processing of input and output domain names,
    respectively. When running on a TTY, the +noidnin and +noidnout
    options may be used to disable IDN processing of input and output
    domain names.

  * The configuration option max-ncache-ttl cannot exceed seven days.
    Previously, larger values than this were silently lowered; now, they
    trigger a configuration error.

  * The new dig -r command line option disables reading of the file $HOME
    /.digrc.

  * Zone signing and key maintenance events are now logged to the dnssec
    category rather than zone.

License

BIND is open source software licenced under the terms of the Mozilla
Public License, version 2.0 (see the LICENSE file for the full text).

The license requires that if you make changes to BIND and distribute them
outside your organization, those changes must be published under the same
license. It does not require that you publish or disclose anything other
than the changes you have made to our software. This requirement does not
affect anyone who is using BIND, with or without modifications, without
redistributing it, nor anyone redistributing BIND without changes.

Those wishing to discuss license compliance may contact ISC at https://
www.isc.org/mission/contact/.

End of Life

The end of life date for BIND 9.14 has not yet been determined. For those
needing long term support, the current Extended Support Version (ESV) is
BIND 9.11, which will be supported until at least December 2021. See
https://www.isc.org/downloads/software-support-policy/ for details of
ISC's 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/.
