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Kea 1.4.0-beta Release Notes

  • Updated on 13 Sep 2018
  • 16 minutes to read
  • Contributors 

Kea 1.4.0-beta, May 18 2018, Release Notes

Welcome to the 1.4.0-beta release of Kea. Kea is a DHCP implementation developed by Internet Systems Consortium, Inc. that features fully functional DHCPv4 and DHCPv6 servers, a dynamic DNS update daemon, a Control Agent (CA) that provides a REST API to control the DHCP servers, an example shell client to connect to the CA and a DHCP performance measurement tool. Both DHCP servers fully support server discovery, address assignment, renewal, rebinding, release, decline, information request, DNS updates, client classification and host reservations. The DHCPv6 server also supports prefix delegation. Lease information can be stored in a MySQL, PostgreSQL or Cassandra database; it can also be stored in a CSV file. Host reservations can be stored in a configuration file; they can also be stored in a MySQL, PostgreSQL, Cassandra databases and to some degree also retrieved from a RADIUS server.

Version 1.4.0-beta adds the following features to Kea:

  • Database improvements - Many Kea users report using multiple Kea instances sharing a single database backend, or cluster of databases. One of the frequently requested features was the ability to report accurate statistics in this case. This surprisingly tricky problem was solved for MySQL and PostgreSQL by a new stat_cmds hook library and schema updates. Users also requested the ability to reconnect after the database connection is lost for whatever reason.

  • Cassandra - Kea has had experimental support for a Cassandra database backend for a while, but the feature hadn't been finished or fully tested. This has changed: the code now supports host reservations and has a great number of new smaller fixes and improvements. Its is now both easier to install and much better documented. Thank you to Deutsche Telekom AG for sponsoring this work.

  • Classification - It is now possible to specify client classes on a pool level, so you can control who is able to use specific pools, group similar clients together or even reject clients that don't meet certain class requirements. Class expressions have expanded capabilities. The most popular seems to be a member operator, which determines whether packet is a member of a given class. Complex boolean logic is available. Ever wanted to do member(foo) and not member(bar)? Now you can.

  • Bug fixes and quality of life improvements - With 134 tickets closed, 1.4.0 beta is by far the biggest release we have ever done.

We have also added 2 new features which are dependent on premium hook libraries:

  • RADIUS - Kea can now be integrated with a RADIUS server. Both access and accounting roles are supported. Kea is able to send Access-Request messages and alter its behavior depending on the responses. Specific IP addresses may be assigned (if Framed-IP-Address or Framed-IPv6-Address is received), client can be assigned to specific pool (if Framed-Pool or Framed-IPv6-Pool is received) or denied service altogether (if Access-Reject is received). Kea can also send accounting messages to RADIUS accounting servers. As with other features, this supports both IPv4 and IPv6.

  • High Availability - To provide a highly available service, despite server failure, two Kea instances can now be configured to run as a pair. Two modes are supported. In hot standby mode there is a primary instance handling all traffic and sending updates to its secondary partner. The secondary monitors the health of the primary and is able to take over automatically in case the primary fails. In load balancing mode both partners are active and are handling approximately half of the traffic traffic. In case of a failure of either server, the partner is able to take over responding to all traffic directed to both servers. Support for additional backup servers is implemented. The backup server's database is updated as soon as possible after changes are made to the primary server's database, so that it can be used as an almost drop-in replacement in case of catastrophic failures that take out both primary and secondary servers. The solution supports both IPv4 and IPv6 and can work with any backend, including memfile. Note that this is NOT an implementation of the IETF standard DHCPv4 failover (which does not support DHCPv6).


Kea 1.4.0-beta is released under the Mozilla Public License, version 2.0.


The premium hook libraries are provided in source code form, under the terms of an End User License Agreement (you are not permitted to redistribute).

Testing premium hooks

ISC Kea support customers will receive tickets inviting them to beta test the premium hooks, which are included with the support subscription. If you are interested in testing premium hooks and do not have Kea support contract, please contact [mailto:info@isc.org](info at isc dot org) to apply to beta test. We will give you a 100% discount coupon in exchange for your help in improving the software. Please let us know when you email which premium hook package(s) you want to test.


The Kea 1.4.0-beta source may be downloaded from:


A PGP signature of the distribution is at:


The signature was generated with the ISC code signing key which is available at:


ISC provides detailed documentation, including installation instructions and usage tutorials in the Kea Administrator Reference Manual. Documentation is included with the installation or via https://kea.isc.org/docs in HTML, plain text, or PDF formats. ISC maintains a public open source code tree at https://github.com/isc-projects/kea and wiki pages with roadmap and issue tracking at https://kea.isc.org.

Limitations and known issues with this release can be found at:


We'd like users of this software to please let us know how it worked for you and what operating system you tested on. Feel free to share your configuration or use case. Also we would like to hear whether the documentation is adequate and accurate (please open tickets for documentation omissions and errors). We want to hear from you even if everything worked.


Professional support for Kea is available from ISC. We encourage all professional users to consider this option: Kea maintenance is funded with support subscriptions. For more information on ISC's DHCP software support see https://www.isc.org/dhcp-subscription/. Free best-effort support is provided by our user community via a mailing list. Information on all public email lists is available at:


If you have any comments or questions about working with Kea, please share them to the Kea Users List https://lists.isc.org/mailman/listinfo/kea-users. Bugs and feature requests may be submitted via the ticket tracking system at https://kea.isc.org.


The following summarizes changes and important upgrade notes since the previous release (1.3.0).

  1. [doc] tomek Hooks package installation instruction added to Kea User's Guide. (Trac #5427, git 7bc5e4297e8b2ccb87d5d5d79ae066fe32964841)

  2. [build] tomek Support for hook packages has been updated. The --with-tierX flags have been removed. Each hook library is now detected independently. (Trac #5619, git aa1f95d699dc664a5660db120ef71edee910a9b3)

  3. [bug] tomek Fixed a crash that was caused by hook library registering new hook points. This fixes unit-tests with forensic logging, but the problem was generic and could cause other libraries to segfault during unloading or reconfiguration. (Trac #5577, git 2f9d1aa95c16e12fabc50d581b966f20b6d8a950)

  4. [bug] tmark Corrected an issue which caused kea-dhcp4 and kea-dhcp6 servers to unload their hooks libraries upon receipt of the first client message following a dynamic reconfigure. (Trac #5564, git 5111f569bd251c2a98a2e6d958e8f6b640a1802d)

  5. [func] tmark A new hooks library, Stat Cmds, has been added to the open source distribution. This library provides commands for fetching lease allocation statistics using lease backend as the source for lease counts per state. This resolves an issue in deployments, where multiple Kea servers share a common lease backend, which made it difficult to obtain accurate lease statistics. (Trac #5589, git 36f20f1c8b28f629fe2896b817ac0f3c6026fe0e)

  6. [func] tmark Support for fetching lease allocation statistics by subnet-id or subnet-id range has been added to the Cassandra back end. This allows it to be used in conjunction with the Stat Cmds hooks library commands for fetching shared lease statistics. (Trac #5588, git 3fcfefdea5ac838936c2109ecbbbc32eabc8fdba)

  7. [bug] fdupont Fixed bug in configurations where "outbound-interface" parameter was set to "use-routing", which in some cases would reset outbound interface index to a negative value and cause the server to fail to respond to the clients. (Trac #5515, git 9d8d00f1f127ee606f09f7ff6006f0d142aac976)

  8. [bug] marcin A bug in http client library was fixed. The IPv6 address specified in brackets is now supported properly. (Trac #5620, git fe38c4368853e47bc993d6c3844cdddba5effde5)

  9. [bug] tmark The PostgreSQL schema was expanded to include two new tables: lease4-stat and lease6-stat and triggers to update them as leases are modified. This resolves an issue in deployments, where multiple Kea servers share a common PostgreSQL lease database, which made it difficult to obtain accurate lease statistics. Since these statistics are now tracked by the database, they do not have to be recalculated at startup or following reconfiguration. This may result in less processing overhead during these events. The new statistics will be accessible via a new Hooks library, being developed for Kea 1.4 under #5589. (Trac #5587, git 36a0160de0df7789eea224954717be05c08638b7)

  10. [bug] tmark The MySQL schema was expanded to include two new tables: lease4-stat and lease6-stat and triggers to update them as leases are modified. This resolves an issue in deployments, where multiple Kea servers share a common MySQL lease database, which made it difficult to obtain accurate lease statistics. Since these statistics are now tracked by the database, they do not have to be recalculated at startup or following reconfiguration. This may result in less processing overhead during these events. The new statistics will be accessible via a new Hooks library, being developed for Kea 1.4 under #5589. (Trac #5586, git a070c327668c10de3b28f5e249f91d6d16a97ff5)

  11. [doc] marcin Documented High Availability hook library in the Kea Administrator Reference Manual. (Trac #5478, git 3db34400d0331e3d4fc208529eeb18f6abfb6562)

  12. [build] marcin Install new header files introduced since Kea 1.3 release. Also, bumped up libraries version numbers for Kea 1.4 beta release. (Trac #5590, git 64351229a30832735c5a81ac17ca1521aa2483b2)

  13. [func] fdupont, marcin Implemented new hook point "leases6_committed" in the DHCPv6 server. It supports new next step status NEXT_STEP_PARK which causes the server to "park" the client's DHCP packet. (Trac #5458, git 04d6fb0a0ac5b9dff2a02764cc9265f9a2a05ae8)

  14. [func] tmark For both kea-dhcp4 and kea-dhcp6, the "ip-address" parameter in the "relay" element for both subnets and shared networks, has been replaced with a list form, "ip-addresses".
    Configuration parsing will continue to honor the singular form, but it should be considered deprecated. In addition, an omission in 1.3 that caused shared network parsing to ignore the "relay' element has been corrected. (Trac #5535, git f4601abdb657122a8ba5d7784eded773ec01d171)

  15. [doc] tomek User's Guide documentation for RADIUS and Host Cache written. (Trac #5538, git c73337a8ec691874b8ac0b2efcd8708f1a79acbb)

  16. [func] fdupont dhcp6_srv_configured hook point added. (Trac #5530, git 3bb521f6ec8b4e2a1e57ec84b17ee12b0ccf0f83)

  17. [build] tmark Modified configure script to support --with-dhcp-mysql and --with-dhcp-pgsql but emit a deprecation warning message encouraging their replacement with --with-mysql and --with-pgsql. (Trac #5567, git 53761069761ddde44636baa30185322debfe4186)

  18. [func] tmark perfdhcp no longer requires -r (rate) be specified in order to use -D, -n, -p and -t options. (Trac #5115, git c3ba89c56882cac1080899ad201f0c02056eef38)

  19. [func] fdupont Extended comment / user-context support to DHCP-DDNS and Control Agent configuration syntax. (Trac #5495, git fe79959e3bc3c46ccb89661cb27696671a8508b8)

  20. [func] tomek lease4-wipe and lease6-wipe are now able to wipe all leases from all configured subnets if subnet-id specified is 0 or the subnet-id parameter is omitted. (Trac #5543, git ecaf777dff4b8d1100c2a97c4fb1cf8f8e63566d)

  21. [func] fdupont Significant improvements to client classification introduced. The order of classes evaluation has changed from alphabetical to the order of appearance. New 'member' expression allows combination of classes. The new 'only-if-required' and 'require-client-class' parameters controlling the scope of a class have been introduced. (Trac #5474, git 3f2d93f0731fc1858b20e831a7d1f090ea8841fe)

  22. [func] tmark kea-dhcp4 and kea-dhcp6 can now be configured to attempt to reconnect to MySQL backends if connectivity is lost. (Trac #5556, git b31da6f9a3545a2cac228eb17c59d72b6b4823f2)

  23. [func] fdupont Added support for generalized UDP Source Port for DHCP Relay (RFC 8357) for DHCPv4, DHCPv6 and DHCPv4-over-DHCPv6. Note this required changes to the inter-server protocol used by our 4o6 implementation, and is therefore not backward compatible. (Trac #5404, git 2a6049947ad4caaaa697dba8cb7669a09264f0bc)

  24. [bug] marcin Corrected a bug in the libkea-asiolink library which caused the DHCP servers to crash while processing commands over the unix domain socket on some systems. (Trac #5580, git cb5276a24436a9e9ce4d1ab4630e7193a4c2d803)

  25. [func] fdupont Implemented lease6-get-all command in lease_cmds hooks library. (Trac #5469, git a0bb7188df47a0f8020ff57739c5a6ab5f7e9828)

  26. [func, bug] marcin The network_state argument is provided to the callouts in the dhcp4_srv_configured hook point. Also, fixed a couple of minor bugs in the HTTP client classes. (Trac #5470, git 93e2b2198c3163afb81d51fdf5ec547602a12415)

  27. [doc] tomek New parameter subnets-action for network4-del and network6-del commands is now documented. (Trac #5441, git 8b2ffabb3d1ba709f319df2b34d0804ee824446b)

  28. [doc] tomek New parameters for Cassandra are now documented. (Trac #5484, git 56e7026ea2bfab99dbfa1a047dc920ec2f743540)

  29. [func] razvan Cassandra backend improvements: get all IPv4 leases, delete hosts, ability to store fixed DHCPv4 fields (next-server, server-hostname, boot-file-name) and user contexts in host reservations. Also, the ability to store MAC address details in DHCPv6 leases on PostgreSQL has been improved. (Github #70, git 8cd0c1ae416be88baf69c2243e83a429d6d5c965) (Trac #5506, git 8cd0c1ae416be88baf69c2243e83a429d6d5c965) (Trac #5507, git 8cd0c1ae416be88baf69c2243e83a429d6d5c965) (Trac #5508, git 8cd0c1ae416be88baf69c2243e83a429d6d5c965) (Trac #4530, git 8cd0c1ae416be88baf69c2243e83a429d6d5c965)

  30. [func] tmark When encountering errors unpacking vendor specific options, both kea-dhcp4 and kea-dhcp6 will now log the error, skip unpacking any remaining options, and then attempt to process the packet as is. Prior to this the servers would log the issue and then drop the packet. (Trac #5551, git 59ef33ee17672c55cee4ec86ff59737b361a3c21)

  31. [func] tmark kea-dhp4 and kea-dhcp6 can now be configured to attempt to reconnect to Postgresql backends if connectivity is lost. (Trac #5477, git 8e62a058382b2245d418cfbf829776934c638e5e)

  32. [func] marcin Implemented leases parsing from JSON in libkea-dhcpsrv. (Trac #5466, git 84c2a2084b0fb7c086fc6b9502f7ff58b708174e)

  33. [func] marcin Implemented new hook points "dhcp4_srv_configured" and "leases4_committed" in the DHCPv4 server. The latter supports new next step status NEXT_STEP_PARK which causes the server to "park" the client's DHCP packet. (Trac #5457, git af43f07b0e227ccabcdf07a046a64cebb11bdccf)

  34. [bug] fdupont Fixed a bug in JSONfeed tool which did not correctly handle strings and interpret their content. (Trac #5513, git 231e923a85db7fb8305c7baa4d15f766fdf60942)

  35. [bug] tmark Fixed a bug which prevented inserting multiple host reservations where IPv4 address was unspecified or when selected subnet identifier was not specified (5416). Corrected inconsistent data types for subnet id columns in both Postgres and MySQL schemas. Now both schemas support up to MAX UINT32 in all subnet id columns. Exiting databases may be updated without data migration. (Trac #5416, #5522, git d1dd0f2e27ffa49515c17cf68d54f162359b6384)

  36. [bug] marcin Multiple critical performance optimizations in the allocation engine for shared networks. (Trac #5437, git 9d8bcd39802795d48c737a05ef3de3634a28ca4e)

  37. [func] tmark kea-dhcp4 now explicitly logs packets dropped due to a lack message type as a log type DHCP4_PACKET_DROP_0009. Prior to this such packets were logged has having an unsupported message type of 0. (Trac #5553, git ff97e5ffb5f3478be71aae8130b6eff3208bd69a)

  38. [func] fdupont Added initial skeleton implementation for Radius hook library. (Trac #5524, git 832aa23b89eab71875bcbdb1e955eb92fdc0e01a)

  39. [func] fdupont Implemented FNV hashing function. Cassandra backend no longer explicitly depends on OpenSSL. (Trac #5502, git 71de75c3bb099f21fdef0d41806da281d6271287)

  40. [func] fdupont Both DHCPv4 and DHCPv6 servers can now listen on loopback interfaces. This capability requires setting socket type to UDP in DHCPv4. Note the feature has not been thoroughly tested. (Trac #5390, git f38cbd73581a7a0f8634a63cb17f9b60407e3acc)

  41. [func] fdupont Extended forensic (aka legal) logging with database capability. (Trac #5420, git 94bd3cc313e9f2a982ef8f8adf0cf44024c76499)

  42. [func] tmark Added support for automatically recalculating lease statistics to the CQL backend. (Trac #5487, git c807388d581ee1c3e479324f3c399f27feba1c96)

  43. [func] razvan, andrei A new parameter exit-wait-time has been added to perfdhcp. It is now possible to tell perfdhcp to wait certain amount of time after exit conditions are met before actually terminating. (Github #55, git 0cd1178ae092fa0c2f122d0e16fb673b4074a6e6)

  44. [func] razvan, andrei, tomek Support for Google Benchmark has been added. To compile benchmarking support, please use --with-benchmark option. (Github #36, git d6819971410b460d7742c762844e2e75ba580944)

  45. [build,bug] fdupont Cassandra build fixes for macOS. (Trac #5494, git cb0d735628aefd6bca2acc11b73d1f66b45d1c40)

  46. [bug] rcgoodfellow Fixed bug in kea-admin causing error on lease-dump. (Github #61, git 2c9454ec56edc8f3cff8a23329f53ced0d172280)

  47. [func] andreipavelQ,tomek The logging configuration is now applied early, which helps seeing errors in case the new configuration is faulty. (Github #41, git d77fbec5a003a69cab207aa741133015f2657878)

  48. [build] andreipavelQ --with-dhcp-mysql renamed to --with-mysql and --with-dhcp-pgsql renamed to --with-pgsql. These names were leftovers from old BIND10 times when Kea was part of bigger solution that also provided DNS services. Kea is now a stand-alone software, thus the -dhcp- doesn't make sense in those options any more. (Github #40, git 318c9e3d3db9bb938ced27932d8401172529a2ff)

  49. [doc] andreipavelQ Documentation has been upgraded to DocBook 5.0. (Github #39, git 9b6705bd6c534128ec18820ff0cbdd72b7fce9e9)

  50. [func] tomek Lightweight 4over6 options reinstantiated. Definitions for DHCPv6 options 89 through 96 were added back. DHCPv4 v4 Parameters Option 159 has its definition tweaked slightly. (Trac #5514, git 6a4aac2b3bfffe41460db6d1cd3c55b1430aa50c)

  51. [build] andrei Support for coverage tests has been improved. (Github #43, git 1949bb3abf71fb3997044d239eb683095166c39f)

  52. [build,bug] andrei, razvan Various small changes and bugfixes. Thank you to Andrei Pavel and Razvan Becheriu for submitting their patch. (Github #54, git 2efa7494228a1797dff8d9d74107a452c61e2386)

  53. [func] fdupont It is now possible to specify client classification restrictions on per pool basis. This capability will be useful for grouping certain types of devices into specific address and/or prefix pools. (Trac #5425, git 5f3a89d6e32e90cd9cbb2347c7b2208c3e1561e0)

  54. [build] andreipavelQ Compilation parameters unified (every file now includes config.h, several makefile tweaks). (Github #38, git 7206aa79c57be7466c4ab3dd558663c6c4f858b7)

  55. [func] fdupont Several hook points now support next step status DROP. This allows more flexibility with dropping packets from within hooks. (Trac #5443, git ff22a906915a34df327174f550f69a396a05bb2c)

  56. [func] marcin Implemented HTTP client classes in libkea-http. (Trac #5451, git 94267e252b372650e4235389251b49d6f5501322)

  57. [build] fdupont Modified configure.ac to include premium module m4 macros, if the module is present. Prior to this it relied on premium having it's own configure.ac script. (Trac #5400, git 38c4f2fb8fc8c8874a0e4671cc295a049acf675f)

  58. [build] fdupont Added support of boost 1.66.0 ASIO. (Github #60/Trac #5496, git bc2947de4296bd99b74e50e65f272c7ad5312429)

  59. [func] marcin Implemented lease4-get-all command in lease_cmds hooks library. (Trac #5468, git a378ec28489e98df64830d1f26c3bebd20e256b2)

  60. [func] marcin Implemented "force-create" parameter for lease4-update and lease6-update commands. (Trac #5472, git 369245e4c5308a701fd483123f2cb2fd7d3d0966)

  61. [func] andrei, razvan Support for host reservations stored in Cassandra added. The core functionality was added. There are some limitations (delete, client classes, fixed DHCPv4 fields, statistics recount, etc.) These will be addressed in upcoming tickets. (github #37, git e37606fd2d0c02234a55f7445c52a12b2e7a82ec)

  62. [func] fdupont User-context and comments are now supported in many new scopes: global, shared-network, subnet, pool, host reservation, option, option definition, client-class, control-socket, dhcp-ddns, interfaces, loggers, and for DHCPv6 pd-pool and server-id. (Trac #5351, git 3405a8fa5d391d96cd15874fd3de3ac63ceb33b6)

  63. [bug] fdupont Fixed subnets and host reservations returned by config-get and config-write. (Trac #5452, git c24d057bed2692eaf3cdb6af889122eb582ffede)

  64. [func] razvan, andrei Significant update of Cassandra support. A lot of code for Cassandra Lease Manager has been updated and partially rewritten. (github #35, git 41795494720cd9886c1e98d21eaeefd94d674e37)

  65. [func] marcin Added support for "dhcp-enable" and "dhcp-disable" commands in the DHCPv4 and DHCPv6 server. (Trac #5442, git 36dc68ff7aa8b3cfd265c4f982d10248590039bd)

  66. [doc] marcin Updated User's Guide describing how to selectively disable legal logging for a subnet. (Trac #5407, git 469080abd711f8e88a5133f76f4ab31a5549a858)

  67. [func] marcin Persistent HTTP/1.1 connections and HTTP/1.0 keep-alive are supported by RESTful API. (Trac #5448, git 05018f7cc0662d6956b9b7648646e0c17da948ba)

  68. [doc] marcin Added placeholder section for the libdhcp_ha hooks library. (Trac #5447, git d939b5b8bc4befb24daf863f2408d97493e4bfbf)

  69. [bug] marcin DHCPv6 server always sends prefixes with the lifetime of 0 for the prefix leases that should no longer be used, even if those prefixes are not included in the Renew/Rebind. (Trac #5403, git 91bb0855ff7ef86ff72b5a946ae716798d7bebc1)

  70. [bug] marcin Fixed a bug which prevented inserting multiple host reservations where IPv4 address was unspecified or when selected subnet identifier was not specified. This change affects both Postgres and MySQL backend. (Trac #5416, git 03fab8f7d5c2e8a5ea735b11ff75652aa31d791d)

Thank you again 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 https://www.isc.org/donate.

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