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<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="noteversion.xml"/>

<section xml:id="relnotes_intro"><info><title>Introduction</title></info>

<para>

BIND 9.11.0 is a new feature release of BIND, still under development.

This document summarizes new features and functional changes that

have been introduced on this branch. With each development

release leading up to the final BIND 9.11.0 release, this document

will be updated with additional features added and bugs fixed.

</para>

</section>

<section xml:id="relnotes_download"><info><title>Download</title></info>

<para>

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

<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.isc.org/downloads/">http://www.isc.org/downloads/</link>.

There you will find additional information about each release,

source code, and pre-compiled versions for Microsoft Windows

operating systems.

</para>

</section>

<section xml:id="relnotes_security"><info><title>Security Fixes</title></info>

<itemizedlist>

<listitem>

<para>

Duplicate EDNS COOKIE options in a response could trigger

an assertion failure. This flaw is disclosed in CVE-2016-2088.

[RT #41809]

</para>

</listitem>

<listitem>

<para>

Insufficient testing when parsing a message allowed

records with an incorrect class to be be accepted,

triggering a REQUIRE failure when those records

were subsequently cached. This flaw is disclosed

in CVE-2015-8000. [RT #40987]

</para>

</listitem>

<listitem>

<para>

Incorrect reference counting could result in an INSIST

failure if a socket error occurred while performing a

lookup. This flaw is disclosed in CVE-2015-8461. [RT#40945]

</para>

</listitem>

<listitem>

<para>

An incorrect boundary check in the OPENPGPKEY rdatatype

could trigger an assertion failure. This flaw is disclosed

in CVE-2015-5986. [RT #40286]

</para>

</listitem>

<listitem>

<para>

A buffer accounting error could trigger an assertion failure

when parsing certain malformed DNSSEC keys.

</para>

<para>

This flaw was discovered by Hanno B&ouml;ck of the Fuzzing

Project, and is disclosed in CVE-2015-5722. [RT #40212]

</para>

</listitem>

<listitem>

<para>

A specially crafted query could trigger an assertion failure

in message.c.

</para>

<para>

This flaw was discovered by Jonathan Foote, and is disclosed

in CVE-2015-5477. [RT #40046]

</para>

</listitem>

<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>

<listitem>

<para>

Specific APL data could trigger an INSIST. This flaw

is disclosed in CVE-2015-8704. [RT #41396]

</para>

</listitem>

<listitem>

<para>

Certain errors that could be encountered when printing out

or logging an OPT record containing a CLIENT-SUBNET option

could be mishandled, resulting in an assertion failure.

This flaw is disclosed in CVE-2015-8705. [RT #41397]

</para>

</listitem>

<listitem>

<para>

Malformed control messages can trigger assertions in named

and rndc. This flaw is disclosed in CVE-2016-1285. [RT

#41666]

</para>

</listitem>

<listitem>

<para>

The resolver could abort with an assertion failure due to

improper DNAME handling when parsing fetch reply

messages. This flaw is disclosed in CVE-2016-1286. [RT #41753]

</para>

</listitem>

</itemizedlist>

</section>

<section xml:id="relnotes_features"><info><title>New Features</title></info>

<itemizedlist>

<listitem>

<para>

Added support for DynDB, a new interface for loading zone data

from an external database, developed by Red Hat for the FreeIPA

project. (Thanks in particular to Adam Tkac and Petr

Spacek of Red Hat for the contribution.)

</para>

<para>

Unlike the existing DLZ and SDB interfaces, which provide a

limited subset of database functionality within BIND &mdash;

translating DNS queries into real-time database lookups with

relatively poor performance and with no ability to handle

DNSSEC-signed data &mdash; DynDB is able to fully implement

and extend the database API used natively by BIND.

</para>

<para>

A DynDB module could pre-load data from an external data

source, then serve it with the same performance and

functionality as conventional BIND zones, and with the

ability to take advantage of database features not

available in BIND, such as multi-master replication.

</para>

</listitem>

<listitem>

<para>

New quotas have been added to limit the queries that are

sent by recursive resolvers to authoritative servers

experiencing denial-of-service attacks. When configured,

these options can both reduce the harm done to authoritative

servers and also avoid the resource exhaustion that can be

experienced by recursives when they are being used as a

vehicle for such an attack.

</para>

<itemizedlist>

<listitem>

<para>

<option>fetches-per-server</option> 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

<option>fetch-quota-params</option> option.

</para>

</listitem>

<listitem>

<para>

<option>fetches-per-zone</option> 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.)

</para>

</listitem>

</itemizedlist>

<para>

Statistics counters have also been added to track the number

of queries affected by these quotas.

</para>

</listitem>

<listitem>

<para>

Added support for <command>dnstap</command>, a fast,

flexible method for capturing and logging DNS traffic,

developed by Robert Edmonds at Farsight Security, Inc.,

whose assistance is gratefully acknowledged.

</para>

<para>

To enable <command>dnstap</command> at compile time,

the <command>fstrm</command> and <command>protobuf-c</command>

libraries must be available, and BIND must be configured with

<option>--enable-dnstap</option>.

</para>

<para>

A new utility <command>dnstap-read</command> has been added

to allow <command>dnstap</command> data to be presented in

a human-readable format.

</para>

<para>

For more information on <command>dnstap</command>, see

<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://dnstap.info">http://dnstap.info</link>.

</para>

</listitem>

<listitem>

<para>

New statistics counters have been added to track traffic

sizes, as specified in RSSAC002. Query and response

message sizes are broken up into ranges of histogram buckets:

TCP and UDP queries of size 0-15, 16-31, ..., 272-288, and 288+,

and TCP and UDP responses of size 0-15, 16-31, ..., 4080-4095,

and 4096+. These values can be accessed via the XML and JSON

statistics channels at, for example,

<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://localhost:8888/xml/v3/traffic">http://localhost:8888/xml/v3/traffic</link>

or

<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://localhost:8888/json/v1/traffic">http://localhost:8888/json/v1/traffic</link>.

</para>

</listitem>

<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 1 second

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>

<command>dig +mapped</command> can now be used to determine

if mapped IPv4 addresses can be used.

</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>

<listitem>

<para>

The following types have been implemented: CSYNC, NINFO, RKEY,

SINK, TA, TALINK.

</para>

</listitem>

<listitem>

<para>

A new <command>message-compression</command> option can be

used to specify whether or not to use name compression when

answering queries. Setting this to <userinput>no</userinput>

results in larger responses, but reduces CPU consumption and

may improve throughput. The default is <userinput>yes</userinput>.

</para>

</listitem>

<listitem>

<para>

A "read-only" clause is now available for non-destructive

control channel access. In such cases, a restricted set of

rndc commands are allowed for querying information from named.

By default, control channel access is read-write.

</para>

</listitem>

<listitem>

<para>

When loading managed signed zones detect if the RRSIG's

inception time is in the future and regenerate the RRSIG

immediately. This helps when the system's clock needs to

be reset backwards.

</para>

</listitem>

</itemizedlist>

</section>

<section xml:id="relnotes_changes"><info><title>Feature Changes</title></info>

<itemizedlist>

<listitem>

<para>

The timers returned by the statistics channel (indicating current

time, server boot time, and most recent reconfiguration time) are

now reported with millisecond accuracy. [RT #40082]

</para>

</listitem>

<listitem>

<para>

Updated the compiled in addresses for H.ROOT-SERVERS.NET.

</para>

</listitem>

<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

answers, 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 been replaced with the COOKIE

option (code point 10). It is no longer experimental, and

is sent by default, by both <command>named</command> and

<command>dig</command>.

</para>

<para>

The SIT-related named.conf options have been marked as

obsolete, and are otherwise ignored.

</para>

</listitem>

<listitem>

<para>

When <command>dig</command> receives a truncated (TC=1)

response or a BADCOOKIE response code from a server, it

will automatically retry the query using the server COOKIE

that was returned by the server in its initial 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>

<listitem>

<para>

Within the <option>response-policy</option> option, it is now

possible to configure RPZ rewrite logging on a per-zone basis

using the <option>log</option> clause.

</para>

</listitem>

<listitem>

<para>

The default preferred glue is now the address type of the

transport the query was received over.

</para>

</listitem>

<listitem>

<para>

On machines with 2 or more processors (CPU), the default value

for the number of UDP listeners has been changed to the number

of detected processors minus one.

</para>

</listitem>

<listitem>

<para>

Zone transfers now use smaller message sizes to improve

message compression. This results in reduced network usage.

</para>

</listitem>

<listitem>

<para>

Added support for the type AVC.

</para>

</listitem>

</itemizedlist>

</section>

<section xml:id="relnotes_port"><info><title>Porting Changes</title></info>

<itemizedlist>

<listitem>

<para>

None.

</para>

</listitem>

</itemizedlist>

</section>

<section xml:id="relnotes_bugs"><info><title>Bug Fixes</title></info>

<itemizedlist>

<listitem>

<para>

None.

</para>

</listitem>

</itemizedlist>

</section>

<section xml:id="end_of_life"><info><title>End of Life</title></info>

<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.

<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.isc.org/downloads/software-support-policy/">https://www.isc.org/downloads/software-support-policy/</link>

</para>

</section>

<section xml:id="relnotes_thanks"><info><title>Thank You</title></info>

<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

<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.isc.org/donate/">http://www.isc.org/donate/</link>.

</para>

</section>

</section>