BIND 9.7.4rc1 is the first release candidate of BIND 9.7.4.

This document summarizes changes from BIND 9.7.3 to BIND 9.7.4rc1. Please see the CHANGES file in the source code release for a complete list of all changes.


The latest version of BIND 9 software can always be found on our web site at There you will find additional information about each release, source code, and some pre-compiled versions for certain operating systems.


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New Features


  • A new test has been added to check the apex NSEC3 records after DNSKEY records have been added via dynamic update. [RT #23229]
  • Added a tool able to generate malformed packets to allow testing of how named handles them. [RT #24096]

Feature Changes


  • Merged in the NetBSD ATF test framework (currently version 0.12) for development of future unit tests. Use configure --with-atf to build ATF internally or configure --with-atf=prefix to use an external copy. [RT #23209]
  • Added more verbose error reporting from DLZ LDAP. [RT #23402]
  • Replaced compile time constant with STDTIME_ON_32BITS. [RT #23587]

Security Fixes


  • Change #2912 (see CHANGES) exposed a latent bug in the DNS message processing code that could allow certain UPDATE requests to crash named. [RT #24777] [CVE-2011-2464]
  • named, set up to be a caching resolver, is vulnerable to a user querying a domain with very large resource record sets (RRSets) when trying to negatively cache the response. Due to an off-by-one error, caching the response could cause named to crash. [RT #24650] [CVE-2011-1910]

Bug Fixes


  • Improved the mechanism for flagging database entries as negative cache records; the former method, RR type 0, could be ambiguous. [RT #24777]
  • During RFC5011 processing some journal write errors were not detected. This could lead to managed-keys changes being committed but not recorded in the journal files, causing potential inconsistencies during later processing. [RT #20256]
  • A potential NULL pointer deference in the DNS64 code could cause named to terminate unexpectedly. [RT #20256]
  • A state variable relating to DNSSEC could fail to be set during some infrequently-executed code paths, allowing it to be used whilst in an unitialized state during cache updates, with unpredictable results. [RT #20256]
  • A potential NULL pointer deference in DNSSEC signing code could cause named to terminate unexpectedly [RT #20256]
  • Several cosmetic code changes were made to silence warnings generated by a static code analysis tool. [RT #20256]
  • When using the -x (sign with only KSK) option on dnssec-signzone, it could incorrectly count the number of ZSKs in the zone. (And in 9.9.0, some code cleanup and improved warning messages). [RT #20852]
  • When using _builtin in named.conf, named.conf changes were not found when reloading the config file. Now checks _builtin zone arguments to see if the zone is re-usable or not. [RT #21914]
  • After an external code review, a code cleanup was done. [RT #22521]
  • After an "rndc reconfig", the refresh timer for managed-keys is ignored, resulting in managed-keys not being refreshed until named is restarted. [RT #22296]
  • Running dnssec-settime -f on an old-style key will now force the key to be rewritten to the new key format even if no other change has been specified, using "-P now -A now" as default values. [RT #22474]
  • Cause named to terminate at startup or rndc reconfig reload to fail, if a log file specified in the conf file isn't a plain file. (RT #22771]
  • named now forces the ADB cache time for glue related data to zero instead of relying on TTL. This corrects problematic behavior in cases where a server was authoritative for the A record of a nameserver for a delegated zone and was queried to recursively resolve records within that zone. [RT #22842]
  • When a validating resolver got a NODATA response for DNSKEY, it was not caching the NODATA. Fixed and test added. [RT #22908]
  • Fixed a bug in which zone keys that were published and but not immediately activated, automatic signing could fail to trigger. [RT #22911]
  • Fixed a possible deadlock due to zone re-signing. [RT #22964]
  • Fixed precedence order bug with NS and DNAME records if both are present. (Also fixed timing of autosign test in 9.7+) [RT #23035]
  • When a DNSSEC signed dynamic zone's signatures need to be refreshed, named would first delete the old signatures in the zone. If a private key of the same algorithm isn't available to named, the signing would fail but the old signatures would already be deleted. named now checks if it can access the private key before deleting the old signatures and leaves the old signature if no private key is found. [RT #23136]
  • When using auto-dnssec and updating DNSKEY records, named did correctly update the zone. [RT #23232]
  • If a slave initiates a TSIG signed AXFR from the master and the master fails to correctly TSIG sign the final message, the slave would be left with the zone in an unclean state. named detected this error too late and named would crash with an INSIST. The order dependancy has been fixed. [RT #23254]
  • Fixed last autosign test report. [RT #23256]
  • named didn't save gid at startup and later assumed gid 0. named now saves/restores the gid when creating creating at startup. [RT #23290]
  • If the server has an IPv6 address but does not have IPv6 connectivity to the internet, dig +trace could fail attempting to use IPv6 addresses. [RT #23297]
  • If named is configured with managed zones, the managed key maint timer can exercise a race condition that can crash the server. [RT #23303]
  • Changing TTL did not cause dnssec-signzone to generate new signatures. [RT #23330]
  • Have the validating resolver use RRSIG original TTL to compute validated RRset and RRSIG TTL. [RT #23332]
  • In "make test" bin/tests/resolver, hold the socket manager lock while freeing the socket. [RT #23333]
  • If named encountered a CNAME instead of a DS record when walking the chain of trust down from the trust anchor, it incorrectly stopped validating. [RT #23338]
  • RRSIG records could have time stamps too far in the future. [RT #23356]
  • named stores cached data in an in-memory database and keeps track of how recently the data is used with a heap. The heap is stored within the cache's memory space. Under a sustained high query load and with a small cache size, this could lead to the heap exhausting the cache space. This would result in cache misses and SERVFAILs, with named never releasing the cache memory the heap used up and never recovering. This fix removes the heap into its own memory space, preventing the heap from exhausting the cache space and allowing named to recover gracefully when the high query load abates. [RT #23371]
  • If "dnssec-lookaside auto" is turned on, named pulled in all keys defined in bind.keys, including the root key. named now only loads the desired keys. [RT #23372]
  • Fully separated key management on a per view basis. [RT #23419]
  • If running on a powerpc CPU and with atomic operations enabled, named could lock up. Added sync instructions to the end of atomic operations. [RT #23469]
  • If OpenSSL was built without engine support, named would have compile errors and fail to build. [RT #23473]
  • "rndc secroots" would abort on the first error and so could miss remaining views. [RT #23488]
  • Handle isc_event_allocate failures in t_tasks test. [RT #23572]
  • ixfr-from-differences {master|slave}; failed to select the master/slave zones, resulting in on diff/journal file being created. [RT #23580]
  • If a DNAME substitution failed, named returned NOERROR. The correct response should be YXDOMAIN. [RT #23591]
  • dns_dnssec_findzonekeys{2} used a inconsistant timestamp when determining which keys are active. This could result in some RRsets not being signed/re-signed. [RT #23642]
  • Remove bin/tests/system/logfileconfig/ns1/named.conf and add in order to resolve changing named.conf issue. [RT #23687]
  • NOTIFY messages were not being sent when generating a NSEC3 chain incrementally. [RT #23702]
  • Zones using automatic key maintenance could fail to check the key repository for updates. named now checks once per hour and the automatic check bug has been fixed. [RT #23744]
  • Signatures for records at the zone apex could go stale due to an incorrect timer setting. [RT #23769]
  • The autosign tests attempted to open ports within reserved ranges. Test now avoids those ports. [RT #23957]
  • Clean up some cross-compiling issues and added two undocumented configure options, --with-gost and --with-rlimtype, to allow over-riding default settings (gost=no and rlimtype="long int") when cross-compiling. [RT #24367]
  • When trying sign with NSEC3, if dnssec-signzone couldn't find the KSK, it would give an incorrect error "NSEC3 iterations too big for weakest DNSKEY strength" rather than the correct "failed to find keys at the zone apex: not found" [RT #24369]
  • Improved consistency checks for dnssec-enable and dnssec-validation, added test cases to the checkconf system test. [RT #24398]
  • nsupdate could dump core on shutdown when using SIG(0) keys. [RT #24604]
  • Named could fail to validate zones list in a DLV that validated insecure without using DLV and had DS records in the parent zone. [RT #24631]

Known issues in this release

  • None

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