<?xml version="1.0" encoding="utf-8"?>

<sect1 xmlns:xi="http://www.w3.org/2001/XInclude">

<xi:include href="noteversion.xml"/>

<sect2 id="relnotes_intro">

<title>Introduction</title>

<para>

This document summarizes changes since the last production release

of BIND on the corresponding major release branch.

</para>

</sect2>

<sect2 id="relnotes_download">

<title>Download</title>

<para>

The latest versions of BIND 9 software can always be found at

<ulink url="http://www.isc.org/downloads/"

>http://www.isc.org/downloads/</ulink>.

There you will find additional information about each release,

source code, and pre-compiled versions for Microsoft Windows

operating systems.

</para>

</sect2>

<sect2 id="relnotes_security">

<title>Security Fixes</title>

<itemizedlist>

<listitem>

<para>

On servers configured to perform DNSSEC validation, an

assertion failure could be triggered on answers from

a specially configured server.

</para>

<para>

This flaw was discovered by Breno Silveira Soares, and is

disclosed in CVE-2015-4620. [RT #39795]

</para>

</listitem>

<listitem>

<para>

On servers configured to perform DNSSEC validation using

managed trust anchors (i.e., keys configured explicitly

via <command>managed-keys</command>, or implicitly

via <command>dnssec-validation auto;</command> or

<command>dnssec-lookaside auto;</command>), revoking

a trust anchor and sending a new untrusted replacement

could cause <command>named</command> to crash with an

assertion failure. This could occur in the event of a

botched key rollover, or potentially as a result of a

deliberate attack if the attacker was in position to

monitor the victim's DNS traffic.

</para>

<para>

This flaw was discovered by Jan-Piet Mens, and is

disclosed in CVE-2015-1349. [RT #38344]

</para>

</listitem>

<listitem>

<para>

A flaw in delegation handling could be exploited to put

<command>named</command> into an infinite loop, in which

each lookup of a name server triggered additional lookups

of more name servers. This has been addressed by placing

limits on the number of levels of recursion

<command>named</command> will allow (default 7), and

on the number of queries that it will send before

terminating a recursive query (default 50).

</para>

<para>

The recursion depth limit is configured via the

<option>max-recursion-depth</option> option, and the query limit

via the <option>max-recursion-queries</option> option.

</para>

<para>

The flaw was discovered by Florian Maury of ANSSI, and is

disclosed in CVE-2014-8500. [RT #37580]

</para>

</listitem>

<listitem>

<para>

Two separate problems were identified in BIND's GeoIP code that

could lead to an assertion failure. One was triggered by use of

both IPv4 and IPv6 address families, the other by referencing

a GeoIP database in <filename>named.conf</filename> which was

not installed. Both are covered by CVE-2014-8680. [RT #37672]

[RT #37679]

</para>

<para>

A less serious security flaw was also found in GeoIP: changes

to the <command>geoip-directory</command> option in

<filename>named.conf</filename> were ignored when running

<command>rndc reconfig</command>. In theory, this could allow

<command>named</command> to allow access to unintended clients.

</para>

</listitem>

</itemizedlist>

</sect2>

<sect2 id="relnotes_features">

<title>New Features</title>

<itemizedlist>

<listitem>

<para>

The serial number of a dynamically updatable zone can

now be set using

<command>rndc signing -serial <replaceable>number</replaceable> <replaceable>zonename</replaceable></command>.

This is particularly useful with <option>inline-signing</option>

zones that have been reset. Setting the serial number to a value

larger than that on the slaves will trigger an AXFR-style

transfer.

</para>

</listitem>

<listitem>

<para>

When answering recursive queries, SERVFAIL responses can now be

cached by the server for a limited time; subsequent queries for

the same query name and type will return another SERVFAIL until

the cache times out. This reduces the frequency of retries

when a query is persistently failing, which can be a burden

on recursive serviers. The SERVFAIL cache timeout is controlled

by <option>servfail-ttl</option>, which defaults to 10 seconds

and has an upper limit of 30.

</para>

</listitem>

<listitem>

<para>

The new <command>rndc nta</command> command can now 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. NTAs are strictly

temporary; by default they expire after one hour, but can be

configured to last up to one week. The default NTA lifetime

can be changed by setting the <option>nta-lifetime</option> in

<filename>named.conf</filename>. When added, NTAs are stored in a

file (<filename><replaceable>viewname</replaceable>.nta</filename>)

in order to persist across restarts of the <command>named</command> server.

</para>

</listitem>

<listitem>

<para>

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

authoritative servers; if a query contains an ECS option then

ACLs containing <option>geoip</option> or <option>ecs</option>

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.

</para>

</listitem>

<listitem>

<para>

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.

</para>

</listitem>

<listitem>

<para>

A new <option>masterfile-style</option> zone option controls

the formatting of text zone files: When set to

<literal>full</literal>, the zone file will dumped in

single-line-per-record format.

</para>

</listitem>

<listitem>

<para>

<command>dig +ednsopt</command> can now be used to set

arbitrary EDNS options in DNS requests.

</para>

</listitem>

<listitem>

<para>

<command>dig +ednsflags</command> can now be used to set

yet-to-be-defined EDNS flags in DNS requests.

</para>

</listitem>

<listitem>

<para>

<command>dig +[no]ednsnegotiation</command> can now be used enable /

disable EDNS version negotiation.

</para>

</listitem>

<listitem>

<para>

<command>dig +header-only</command> can now be used to send

queries without a question section.

</para>

</listitem>

<listitem>

<para>

<command>dig +ttlunits</command> causes <command>dig</command>

to print TTL values with time-unit suffixes: w, d, h, m, s for

weeks, days, hours, minutes, and seconds.

</para>

</listitem>

<listitem>

<para>

<command>dig +zflag</command> can be used to set the last

unassigned DNS header flag bit. This bit in normally zero.

</para>

</listitem>

<listitem>

<para>

<command>dig +dscp=<replaceable>value</replaceable></command>

can now be used to set the DSCP code point in outgoing query

packets.

</para>

</listitem>

<listitem>

<para>

<option>serial-update-method</option> can now be set to

<literal>date</literal>. On update, the serial number will

be set to the current date in YYYYMMDDNN format.

</para>

</listitem>

<listitem>

<para>

<command>dnssec-signzone -N date</command> also sets the serial

number to YYYYMMDDNN.

</para>

</listitem>

<listitem>

<para>

<command>named -L <replaceable>filename</replaceable></command>

causes <command>named</command> to send log messages to the specified file by

default instead of to the system log.

</para>

</listitem>

<listitem>

<para>

The rate limiter configured by the

<option>serial-query-rate</option> option no longer covers

NOTIFY messages; those are now separately controlled by

<option>notify-rate</option> and

<option>startup-notify-rate</option> (the latter of which

controls the rate of NOTIFY messages sent when the server

is first started up or reconfigured).

</para>

</listitem>

<listitem>

<para>

The default number of tasks and client objects available

for serving lightweight resolver queries have been increased,

and are now configurable via the new <option>lwres-tasks</option>

and <option>lwres-clients</option> options in

<filename>named.conf</filename>. [RT #35857]

</para>

</listitem>

<listitem>

<para>

Log output to files can now be buffered by specifying

<command>buffered yes;</command> when creating a channel.

</para>

</listitem>

<listitem>

<para>

<command>delv +tcp</command> will exclusively use TCP when

sending queries.

</para>

</listitem>

<listitem>

<para>

<command>named</command> will now check to see whether

other name server processes are running before starting up.

This is implemented in two ways: 1) by refusing to start

if the configured network interfaces all return "address

in use", and 2) by attempting to acquire a lock on a file

specified by the <option>lock-file</option> option or

the <command>-X</command> command line option. The

default lock file is

<filename>/var/run/named/named.lock</filename>.

Specifying <literal>none</literal> will disable the lock

file check.

</para>

</listitem>

<listitem>

<para>

<command>rndc delzone</command> can now be applied to zones

which were configured in <filename>named.conf</filename>;

it is no longer restricted to zones which were added by

<command>rndc addzone</command>. (Note, however, that

this does not edit <filename>named.conf</filename>; the zone

must be removed from the configuration or it will return

when <command>named</command> is restarted or reloaded.)

</para>

</listitem>

<listitem>

<para>

<command>rndc modzone</command> can be used to reconfigure

a zone, using similar syntax to <command>rndc addzone</command>.

</para>

</listitem>

<listitem>

<para>

<command>rndc showzone</command> displays the current

configuration for a specified zone.

</para>

</listitem>

<listitem>

<para>

Added server-side support for pipelined TCP queries. Clients

may continue sending queries via TCP while previous queries are

processed in parallel. Responses are sent when they are

ready, not necessarily in the order in which the queries were

received.

</para>

<para>

To revert to the former behavior for a particular

client address or range of addresses, specify the address prefix

in the "keep-response-order" option. To revert to the former

behavior for all clients, use "keep-response-order { any; };".

</para>

</listitem>

<listitem>

<para>

The new <command>mdig</command> command is a version of

<command>dig</command> that sends multiple pipelined

queries and then waits for responses, instead of sending one

query and waiting the response before sending the next. [RT #38261]

</para>

</listitem>

<listitem>

<para>

To enable better monitoring and troubleshooting of RFC 5011

trust anchor management, the new <command>rndc managed-keys</command>

can be used to check status of trust anchors or to force keys

to be refreshed. Also, the managed-keys data file now has

easier-to-read comments. [RT #38458]

</para>

</listitem>

<listitem>

<para>

An <command>--enable-querytrace</command> 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. [RT #37520]

</para>

</listitem>

<listitem>

<para>

A new <command>tcp-only</command> option can be specified

in <command>server</command> statements to force

<command>named</command> to connect to the specified

server via TCP. [RT #37800]

</para>

</listitem>

<listitem>

<para>

The <command>nxdomain-redirect</command> option specifies

a DNS namespace to use for NXDOMAIN redirection. When a

recursive lookup returns NXDOMAIN, a second lookup is

initiated with the specified name appended to the query

name. This allows NXDOMAIN redirection data to be supplied

by multiple zones configured on the server or by recursive

queries to other servers. (The older method, using

a single <command>type redirect</command> zone, has

better average performance but is less flexible.) [RT #37989]

</para>

</listitem>

</itemizedlist>

</sect2>

<sect2 id="relnotes_changes">

<title>Feature Changes</title>

<itemizedlist>

<listitem>

<para>

ACLs containing <command>geoip asnum</command> elements were

not correctly matched unless the full organization name was

specified in the ACL (as in

<command>geoip asnum "AS1234 Example, Inc.";</command>).

They can now match against the AS number alone (as in

<command>geoip asnum "AS1234";</command>).

</para>

</listitem>

<listitem>

<para>

When using native PKCS#11 cryptography (i.e.,

<command>configure --enable-native-pkcs11</command>) HSM PINs

of up to 256 characters can now be used.

</para>

</listitem>

<listitem>

<para>

NXDOMAIN responses to queries of type DS are now cached separately

from those for other types. This helps when using "grafted" zones

of type forward, for which the parent zone does not contain a

delegation, such as local top-level domains. Previously a query

of type DS for such a zone could cause the zone apex to be cached

as NXDOMAIN, blocking all subsequent queries. (Note: This

change is only helpful when DNSSEC validation is not enabled.

"Grafted" zones without a delegation in the parent are not a

recommended configuration.)

</para>

</listitem>

<listitem>

<para>

Update forwarding performance has been improved by allowing

a single TCP connection to be shared between multiple updates.

</para>

</listitem>

<listitem>

<para>

By default, <command>nsupdate</command> will now check

the correctness of hostnames when adding records of type

A, AAAA, MX, SOA, NS, SRV or PTR. This behavior can be

disabled with <command>check-names no</command>.

</para>

</listitem>

<listitem>

<para>

Added support for OPENPGPKEY type.

</para>

</listitem>

<listitem>

<para>

The names of the files used to store managed keys and added

zones for each view are no longer based on the SHA256 hash

of the view name, except when this is necessary because the

view name contains characters that would be incompatible with use

as a file name. For views whose names do not contain forward

slashes ('/'), backslashes ('\'), or capital letters - which

could potentially cause namespace collision problems on

case-insensitive filesystems - files will now be named

after the view (for example, <filename>internal.mkeys</filename>

or <filename>external.nzf</filename>). However, to ensure

consistent behavior when upgrading, if a file using the old

name format is found to exist, it will continue to be used.

</para>

</listitem>

<listitem>

<para>

"rndc" can now return text output of arbitrary size to

the caller. (Prior to this, certain commands such as

"rndc tsig-list" and "rndc zonestatus" could return

truncated output.)

</para>

</listitem>

<listitem>

<para>

Errors reported when running <command>rndc addzone</command>

(e.g., when a zone file cannot be loaded) have been clarified

to make it easier to diagnose problems.

</para>

</listitem>

<listitem>

<para>

When encountering an authoritative name server whose name is

an alias pointing to another name, the resolver treats

this as an error and skips to the next server. Previously

this happened silently; now the error will be logged to

the newly-created "cname" log category.

</para>

</listitem>

<listitem>

<para>

If <command>named</command> is not configured to validate the answer then

allow fallback to plain DNS on timeout even when we know

the server supports EDNS. This will allow the server to

potentially resolve signed queries when TCP is being

blocked.

</para>

</listitem>

<listitem>

<para>

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 <replaceable>number</replaceable>;".

[RT #37927]

</para>

</listitem>

<listitem>

<para>

The experimental SIT option (code point 65001) of BIND

9.10.0 through BIND 9.10.2 has be replace the COOKIE

option (code point 10) and is no longer experimental and

is sent by default.

</para>

<para>

The SIT related named.conf options have been marked as

obsolete and are otherwise ignored.

</para>

</listitem>

<listitem>

<para>

When retrying a query via TCP due to the first answer

being truncated, <command>dig</command> will now correctly

send the Server COOKIE returned by the server in the prior

response. [RT #39047]

</para>

</listitem>

<listitem>

<para>

A alternative NXDOMAIN redirect method (nxdomain-redirect)

which allows the redirect information to be looked up from

a namespace on the Internet rather than requiring a zone

to be configured on the server is now available.

</para>

</listitem>

<listitem>

<para>

Retrieving the local port range from net.ipv4.ip_local_port_range

on Linux is now supported.

</para>

</listitem>

</itemizedlist>

</sect2>

<sect2 id="relnotes_bugs">

<title>Bug Fixes</title>

<itemizedlist>

<listitem>

<para>

<command>dig</command>, <command>host</command> and

<command>nslookup</command> aborted when encountering

a name which, after appending search list elements,

exceeded 255 bytes. Such names are now skipped, but

processing of other names will continue. [RT #36892]

</para>

</listitem>

<listitem>

<para>

The error message generated when

<command>named-checkzone</command> or

<command>named-checkconf -z</command> encounters a

<option>$TTL</option> directive without a value has

been clarified. [RT #37138]

</para>

</listitem>

<listitem>

<para>

Semicolon characters (;) included in TXT records were

incorrectly escaped with a backslash when the record was

displayed as text. This is actually only necessary when there

are no quotation marks. [RT #37159]

</para>

</listitem>

<listitem>

<para>

When files opened for writing by <command>named</command>,

such as zone journal files, were referenced more than once

in <filename>named.conf</filename>, it could lead to file

corruption as multiple threads wrote to the same file. This

is now detected when loading <filename>named.conf</filename>

and reported as an error. [RT #37172]

</para>

</listitem>

<listitem>

<para>

When checking for updates to trust anchors listed in

<option>managed-keys</option>, <command>named</command>

now revalidates keys based on the current set of

active trust anchors, without relying on any cached

record of previous validation. [RT #37506]

</para>

</listitem>

<listitem>

<para>

Large-system tuning

(<command>configure --with-tuning=large</command>) caused

problems on some platforms by setting a socket receive

buffer size that was too large. This is now detected and

corrected at run time. [RT #37187]

</para>

</listitem>

<listitem>

<para>

When NXDOMAIN redirection is in use, queries for a name

that is present in the redirection zone but a type that

is not present will now return NOERROR instead of NXDOMAIN.

</para>

</listitem>

<listitem>

<para>

Due to an inadvertent removal of code in the previous

release, when <command>named</command> encountered an

authoritative name server which dropped all EDNS queries,

it did not always try plain DNS. This has been corrected.

[RT #37965]

</para>

</listitem>

<listitem>

<para>

A regression caused nsupdate to use the default recursive servers

rather than the SOA MNAME server when sending the UPDATE.

</para>

</listitem>

<listitem>

<para>

Adjusted max-recursion-queries to accommodate the smaller

initial packet sizes used in BIND 9.10 and higher when

contacting authoritative servers for the first time.

</para>

</listitem>

<listitem>

<para>

Built-in "empty" zones did not correctly inherit the

"allow-transfer" ACL from the options or view. [RT #38310]

</para>

</listitem>

<listitem>

<para>

Two leaks were fixed that could cause <command>named</command>

processes to grow to very large sizes. [RT #38454]

</para>

</listitem>

<listitem>

<para>

Fixed some bugs in RFC 5011 trust anchor management,

including a memory leak and a possible loss of state

information. [RT #38458]

</para>

</listitem>

<listitem>

<para>

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]

</para>

</listitem>

<listitem>

<para>

A race during shutdown or reconfiguration could

cause an assertion failure in mem.c. [RT #38979]

</para>

</listitem>

<listitem>

<para>

Some answer formatting options didn't work correctly with

<command>dig +short</command>. [RT #39291]

</para>

</listitem>

<listitem>

<para>

Several bugs have been fixed in the RPZ implementation:

</para>

<itemizedlist>

<listitem>

<para>

Policy zones that did not specifically require recursion

could be treated as if they did; consequently, setting

<command>qname-wait-recurse no;</command> was

sometimes ineffective. This has been corrected.

In most configurations, behavioral changes due to this

fix will not be noticeable. [RT #39229]

</para>

</listitem>

<listitem>

<para>

The server could crash if policy zones were updated (e.g.

via <command>rndc reload</command> or an incoming zone

transfer) while RPZ processing was still ongoing for an

active query. [RT #39415]

</para>

</listitem>

<listitem>

<para>

On servers with one or more policy zones configured as

slaves, if a policy zone updated during regular operation

(rather than at startup) using a full zone reload, such as

via AXFR, a bug could allow the RPZ summary data to fall out

of sync, potentially leading to an assertion failure in

rpz.c when further incremental updates were made to the

zone, such as via IXFR. [RT #39567]

</para>

</listitem>

<listitem>

<para>

The server could match a shorter prefix than what was

available in CLIENT-IP policy triggers, and so, an

unexpected action could be taken. This has been

corrected. [RT #39481]

</para>

</listitem>

<listitem>

<para>

The server could crash if a reload of an RPZ zone was

initiated while another reload of the same zone was

already in progress. [RT #39649]

</para>

</listitem>

</itemizedlist>

</listitem>

</itemizedlist>

</sect2>

<sect2 id="end_of_life">

<title>End of Life</title>

<para>

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.

<ulink url="https://www.isc.org/downloads/software-support-policy/"

>https://www.isc.org/downloads/software-support-policy/</ulink>

</para>

</sect2>

<sect2 id="relnotes_thanks">

<title>Thank You</title>

<para>

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

<ulink url="http://www.isc.org/donate/"

>http://www.isc.org/donate/</ulink>.

</para>

</sect2>

</sect1>