HISTORY Functional enhancements from prior major releases of BIND 9 BIND 9.14 BIND 9.14 (a stable branch based on the 9.13 development branch) includes a number of changes from BIND 9.12 and earlier releases. New features include: * A new "plugin" mechanism has been added to allow query functionality to be extended using dynamically loadable libraries. The "filter-aaaa" feature has been removed from named and is now implemented as a plugin. * Socket and task code has been refactored to improve performance. * QNAME minimization, as described in RFC 7816, is now supported. * "Root key sentinel" support, enabling validating resolvers to indicate via a special query which trust anchors are configured for the root zone. * Secondary zones can now be configured as "mirror" zones; their contents are transferred in as with traditional slave zones, but are subject to DNSSEC validation and are not treated as authoritative data when answering. This makes it easier to configure a local copy of the root zone as described in RFC 7706. * The "validate-except" option allows configuration of domains below which DNSSEC validation should not be performed. * The default value of "dnssec-validation" is now "auto". * IDNA2008 is now supported when linking with libidn2. * "named -V" now outputs the default paths for files used by named and other tools. In addition, workarounds that were formerly in place to enable resolution of domains whose authoritative servers did not respond to EDNS queries have been removed. See https://dnsflagday.net for more details. Cryptographic support has been modernized. BIND now uses the best available pseudo-random number generator for the platform on which it's built. Very old versions of OpenSSL are no longer supported. Cryptography is now mandatory: building BIND without DNSSEC is no longer supported. Special code to support certain legacy operating systems has also been removed; see the file PLATFORMS.md for details of supported platforms. In addition to OpenSSL, BIND now requires support for IPv6, threads, and standard atomic operations provided by the C compiler. BIND 9.12 BIND 9.12 includes a number of changes from BIND 9.11 and earlier releases. New features include: * named and related libraries have been substantially refactored for improved query performance -- particularly on delegation heavy zones -- and for improved readability, maintainability, and testability. * Code implementing the name server query processing logic has been moved into a new libns library, for easier testing and use in tools other than named. * Cached, validated NSEC and other records can now be used to synthesize NXDOMAIN responses. * The DNS Response Policy Service API (DNSRPS) is now supported. * Setting 'max-journal-size default' now limits the size of journal files to twice the size of the zone. * dnstap-read -x prints a hex dump of the wire format of each logged DNS message. * dnstap output files can now be configured to roll automatically when reaching a given size. * Log file timestamps can now also be formatted in ISO 8601 (local) or ISO 8601 (UTC) formats. * Logging channels and dnstap output files can now be configured to use a timestamp as the suffix when rolling to a new file. * 'named-checkconf -l' lists zones found in named.conf. * Added support for the EDNS Padding and Keepalive options. * 'new-zones-directory' option sets the location where the configuration data for zones added by rndc addzone is stored. * The default key algorithm in rndc-confgen is now hmac-sha256. * filter-aaaa-on-v4 and filter-aaaa-on-v6 options are now available by default without a configure option. * The obsolete isc-hmac-fixup command has been removed. BIND 9.11 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 ". 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 " 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 9.10.0 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 9.9.0 BIND 9.9.0 includes a number of changes from BIND 9.8 and earlier releases. New features include: * Inline signing, allowing automatic DNSSEC signing of master zones without modification of the zonefile, or "bump in the wire" signing in slaves. * NXDOMAIN redirection. * New 'rndc flushtree' command clears all data under a given name from the DNS cache. * New 'rndc sync' command dumps pending changes in a dynamic zone to disk without a freeze/thaw cycle. * New 'rndc signing' command displays or clears signing status records in 'auto-dnssec' zones. * NSEC3 parameters for 'auto-dnssec' zones can now be set prior to signing, eliminating the need to initially sign with NSEC. * Startup time improvements on large authoritative servers. * Slave zones are now saved in raw format by default. * Several improvements to response policy zones (RPZ). * Improved hardware scalability by using multiple threads to listen for queries and using finer-grained client locking * The 'also-notify' option now takes the same syntax as 'masters', so it can used named masterlists and TSIG keys. * 'dnssec-signzone -D' writes an output file containing only DNSSEC data, which can be included by the primary zone file. * 'dnssec-signzone -R' forces removal of signatures that are not expired but were created by a key which no longer exists. * 'dnssec-signzone -X' allows a separate expiration date to be specified for DNSKEY signatures from other signatures. * New '-L' option to dnssec-keygen, dnssec-settime, and dnssec-keyfromlabel sets the default TTL for the key. * dnssec-dsfromkey now supports reading from standard input, to make it easier to convert DNSKEY to DS. * RFC 1918 reverse zones have been added to the empty-zones table per RFC 6303. * Dynamic updates can now optionally set the zone's SOA serial number to the current UNIX time. * DLZ modules can now retrieve the source IP address of the querying client. * 'request-ixfr' option can now be set at the per-zone level. * 'dig +rrcomments' turns on comments about DNSKEY records, indicating their key ID, algorithm and function * Simplified nsupdate syntax and added readline support BIND 9.8.0 BIND 9.8.0 includes a number of changes from BIND 9.7 and earlier releases. New features include: * Built-in trust anchor for the root zone, which can be switched on via "dnssec-validation auto;" * Support for DNS64. * Support for response policy zones (RPZ). * Support for writable DLZ zones. * Improved ease of configuration of GSS/TSIG for interoperability with Active Directory * Support for GOST signing algorithm for DNSSEC. * Removed RTT Banding from server selection algorithm. * New "static-stub" zone type. * Allow configuration of resolver timeouts via "resolver-query-timeout" option. * The DLZ "dlopen" driver is now built by default. * Added a new include file with function typedefs for the DLZ "dlopen" driver. * Made "--with-gssapi" default. * More verbose error reporting from DLZ LDAP. BIND 9.7.0 BIND 9.7.0 includes a number of changes from BIND 9.6 and earlier releases. Most are intended to simplify DNSSEC configuration. New features include: * Fully automatic signing of zones by "named". * Simplified configuration of DNSSEC Lookaside Validation (DLV). * Simplified configuration of Dynamic DNS, using the "ddns-confgen" command line tool or the "local" update-policy option. (As a side effect, this also makes it easier to configure automatic zone re-signing.) * New named option "attach-cache" that allows multiple views to share a single cache. * DNS rebinding attack prevention. * New default values for dnssec-keygen parameters. * Support for RFC 5011 automated trust anchor maintenance * Smart signing: simplified tools for zone signing and key maintenance. * The "statistics-channels" option is now available on Windows. * A new DNSSEC-aware libdns API for use by non-BIND9 applications * On some platforms, named and other binaries can now print out a stack backtrace on assertion failure, to aid in debugging. * A "tools only" installation mode on Windows, which only installs dig, host, nslookup and nsupdate. * Improved PKCS#11 support, including Keyper support and explicit OpenSSL engine selection. BIND 9.6.0 * Full NSEC3 support * Automatic zone re-signing * New update-policy methods tcp-self and 6to4-self * The BIND 8 resolver library, libbind, has been removed from the BIND 9 distribution and is now available as a separate download. * Change the default pid file location from /var/run to /var/run/ {named,lwresd} for improved chroot/setuid support. BIND 9.5.0 * GSS-TSIG support (RFC 3645). * DHCID support. * Experimental http server and statistics support for named via xml. * More detailed statistics counters including those supported in BIND 8. * Faster ACL processing. * Use Doxygen to generate internal documentation. * Efficient LRU cache-cleaning mechanism. * NSID support. BIND 9.4.0 * Implemented "additional section caching (or acache)", an internal cache framework for additional section content to improve response performance. Several configuration options were provided to control the behavior. * New notify type 'master-only'. Enable notify for master zones only. * Accept 'notify-source' style syntax for query-source. * rndc now allows addresses to be set in the server clauses. * New option "allow-query-cache". This lets "allow-query" be used to specify the default zone access level rather than having to have every zone override the global value. "allow-query-cache" can be set at both the options and view levels. If "allow-query-cache" is not set then "allow-recursion" is used if set, otherwise "allow-query" is used if set unless "recursion no;" is set in which case "none;" is used, otherwise the default (localhost; localnets;) is used. * rndc: the source address can now be specified. * ixfr-from-differences now takes master and slave in addition to yes and no at the options and view levels. * Allow the journal's name to be changed via named.conf. * 'rndc notify zone [class [view]]' resend the NOTIFY messages for the specified zone. * 'dig +trace' now randomly selects the next servers to try. Report if there is a bad delegation. * Improve check-names error messages. * Make public the function to read a key file, dst_key_read_public(). * dig now returns the byte count for axfr/ixfr. * allow-update is now settable at the options / view level. * named-checkconf now checks the logging configuration. * host now can turn on memory debugging flags with '-m'. * Don't send notify messages to self. * Perform sanity checks on NS records which refer to 'in zone' names. * New zone option "notify-delay". Specify a minimum delay between sets of NOTIFY messages. * Extend adjusting TTL warning messages. * Named and named-checkzone can now both check for non-terminal wildcard records. * "rndc freeze/thaw" now freezes/thaws all zones. * named-checkconf now check acls to verify that they only refer to existing acls. * The server syntax has been extended to support a range of servers. * Report differences between hints and real NS rrset and associated address records. * Preserve the case of domain names in rdata during zone transfers. * Restructured the data locking framework using architecture dependent atomic operations (when available), improving response performance on multi-processor machines significantly. x86, x86_64, alpha, powerpc, and mips are currently supported. * UNIX domain controls are now supported. * Add support for additional zone file formats for improving loading performance. The masterfile-format option in named.conf can be used to specify a non-default format. A separate command named-compilezone was provided to generate zone files in the new format. Additionally, the -I and -O options for dnssec-signzone specify the input and output formats. * dnssec-signzone can now randomize signature end times (dnssec-signzone -j jitter). * Add support for CH A record. * Add additional zone data constancy checks. named-checkzone has extended checking of NS, MX and SRV record and the hosts they reference. named has extended post zone load checks. New zone options: check-mx and integrity-check. * edns-udp-size can now be overridden on a per server basis. * dig can now specify the EDNS version when making a query. * Added framework for handling multiple EDNS versions. * Additional memory debugging support to track size and mctx arguments. * Detect duplicates of UDP queries we are recursing on and drop them. New stats category "duplicates". * "USE INTERNAL MALLOC" is now runtime selectable. * The lame cache is now done on a basis as some servers only appear to be lame for certain query types. * Limit the number of recursive clients that can be waiting for a single query () to resolve. New options clients-per-query and max-clients-per-query. * dig: report the number of extra bytes still left in the packet after processing all the records. * Support for IPSECKEY rdata type. * Raise the UDP recieve buffer size to 32k if it is less than 32k. * x86 and x86_64 now have seperate atomic locking implementations. * named-checkconf now validates update-policy entries. * Attempt to make the amount of work performed in a iteration self tuning. The covers nodes clean from the cache per iteration, nodes written to disk when rewriting a master file and nodes destroyed per iteration when destroying a zone or a cache. * ISC string copy API. * Automatic empty zone creation for D.F.IP6.ARPA and friends. Note: RFC 1918 zones are not yet covered by this but are likely to be in a future release. * New options: empty-server, empty-contact, empty-zones-enable and disable-empty-zone. * dig now has a '-q queryname' and '+showsearch' options. * host/nslookup now continue (default)/fail on SERVFAIL. * dig now warns if 'RA' is not set in the answer when 'RD' was set in the query. host/nslookup skip servers that fail to set 'RA' when 'RD' is set unless a server is explicitly set. * Integrate contibuted DLZ code into named. * Integrate contibuted IDN code from JPNIC. * libbind: corresponds to that from BIND 8.4.7. BIND 9.3.0 * DNSSEC is now DS based (RFC 3658). * DNSSEC lookaside validation. * check-names is now implemented. * rrset-order is more complete. * IPv4/IPv6 transition support, dual-stack-servers. * IXFR deltas can now be generated when loading master files, ixfr-from-differences. * It is now possible to specify the size of a journal, max-journal-size. * It is now possible to define a named set of master servers to be used in masters clause, masters. * The advertised EDNS UDP size can now be set, edns-udp-size. * allow-v6-synthesis has been obsoleted. * Zones containing MD and MF will now be rejected. * dig, nslookup name. now report "Not Implemented" as NOTIMP rather than NOTIMPL. This will have impact on scripts that are looking for NOTIMPL. * libbind: corresponds to that from BIND 8.4.5. BIND 9.2.0 * The size of the cache can now be limited using the "max-cache-size" option. * The server can now automatically convert RFC1886-style recursive lookup requests into RFC2874-style lookups, when enabled using the new option "allow-v6-synthesis". This allows stub resolvers that support AAAA records but not A6 record chains or binary labels to perform lookups in domains that make use of these IPv6 DNS features. * Performance has been improved. * The man pages now use the more portable "man" macros rather than the "mandoc" macros, and are installed by "make install". * The named.conf parser has been completely rewritten. It now supports "include" directives in more places such as inside "view" statements, and it no longer has any reserved words. * The "rndc status" command is now implemented. * rndc can now be configured automatically. * A BIND 8 compatible stub resolver library is now included in lib/bind. * OpenSSL has been removed from the distribution. This means that to use DNSSEC, OpenSSL must be installed and the --with-openssl option must be supplied to configure. This does not apply to the use of TSIG, which does not require OpenSSL. * The source distribution now builds on Windows. See win32utils/ readme1.txt and win32utils/win32-build.txt for details. * This distribution also includes a new lightweight stub resolver library and associated resolver daemon that fully support forward and reverse lookups of both IPv4 and IPv6 addresses. This library is considered experimental and is not a complete replacement for the BIND 8 resolver library. Applications that use the BIND 8 res_* functions to perform DNS lookups or dynamic updates still need to be linked against the BIND 8 libraries. For DNS lookups, they can also use the new "getrrsetbyname()" API. * BIND 9.2 is capable of acting as an authoritative server for DNSSEC secured zones. This functionality is believed to be stable and complete except for lacking support for verifications involving wildcard records in secure zones. * When acting as a caching server, BIND 9.2 can be configured to perform DNSSEC secure resolution on behalf of its clients. This part of the DNSSEC implementation is still considered experimental. For detailed information about the state of the DNSSEC implementation, see the file doc/misc/dnssec.