Kea 1.9.9, June 30th 2021, Release Notes
Welcome to Kea 1.9.9, the tenth monthly release of the 1.9 development branch. As with any other development release, use this with caution: development releases are not recommended for production use.
As the 2.0.0 release approaches, we are adding fewer and less significant new features. Instead, there are more bug fixes, documentation edits, and small improvements that are expected from stable software. The most notable changes introduced in this version are:
New GSS-TSIG premium hook - There is work in progress to implement a GSS-TSIG extension, to integrate DNS updates with Windows Active Directory. This subscriber-only hook is not functional yet; however, it is available as a technology preview for customers who would like to take an early look. It provides support for two Kerberos implementations: MIT and Heimdal. It is the first hook that can be loaded by the D2 (dhcp-ddns) daemon [#1884 (closed), #1909 (closed), #1880 (closed)].
dhcp-server-identifier in client class - Kea now allows the definition of a
dhcp-server-identifierin a class scope. This capability is typically not needed, but may be used by advanced users to segregate their traffic based on device types [#1836 (closed)].
The Cassandra lease backend is now deprecated - See the Incompatible Changes section below [#1892 (closed)].
Improvements - Kea now prints much more detailed information about the subnet, when the allocation engine fails to allocate an address. This extra information makes it easier to investigate any problems [#1915 (closed)]. A new debug level 15 has been introduced; log messages are now more consistent regardless of the reason for a drop [#1916 (closed)]. Suboption 1 is treated as PRL/ORO only for DOCSIS packets [#1894 (closed)]. The documentation now builds with older Sphinx versions [#1937 (closed)]. The Kea-admin tool now produces more useful error messages [#1653 (closed)]. The run script hook now has more parameters [#1840 (closed)]. The run script hook now handles signals better [#1720 (closed)].
Bug fixes - The IOService is now destroyed in a safer manner during shutdown, preventing rare crashes during shutdown [#1948 (closed)]. The HA+MT client now correctly logs the number of threads [#1902 (closed)]. A race condition in the database reconnect code has been eliminated [#1861 (closed)]. One case where the run script hook could have left zombie processes in the background has been fixed [#1878 (closed)]. A problem where the PSID field in the MAP option could be set incorrectly under certain conditions has been fixed [#1858 (closed)]. Many previously uninitialized members are now initialized properly [#1845, #1906 (closed)]. Several thread sanitizer warnings have been addressed in the HTTP client tests [#1817 (closed)]. Several compilation warnings have been fixed [#1899 (closed)].
Documentation The ARM has a new appendix dedicated to Kea configuration files. All possible configuration parameters in DHCPv4, DHCPv6, D2, CA, and NETCONF daemons are presented as BNF notation and are generated automatically, which should ensure that this list is kept up to date [#504 (closed), #745 (closed)]. Many corrections have been made to the Kea ARM [#1917 (closed)]. The outdated note about HA+MT being in active development has been removed [#1901 (closed)]. Examples in the forensic logging v4 section in the ARM have been fixed [#1862 (closed)]. Duplicate forensic logging documentation sections have been removed [#1864 (closed)].
Test improvements Several test improvements have been made [#1913, #1941 (closed)]. The perfdhcp testing tool is now able to send RELEASE packets in DHCPv4 [#1119 (closed)]. Hammer, our build tool, now supports FreeBSD 13, Fedora 34, Ubuntu 21.04, and Alpine 3.13 [#1921 (closed), #1658 (closed)]. A mixedSignal unit-test failure on CentOS 7 has been fixed [#1769 (closed)].
Community The Kea project would like to make it easier for people to participate in the software's development, so we chose some tickets that should be easy for newcomers to work on. Look for the
beginnerlabel in our GitLab project. Also, we added the Linux Foundation's Developer's Certificate of Origin to the project. It's a very short statement by which contributors confirm that they are allowed to contribute code [#1895 (closed)].
Config Backend for Postgres. We are working on a Configuration Backend implementation that will use PostgreSQL rather than MySQL. It is unclear whether this feature will be complete in time for 2.0.0; as such, the partial changes made so far are not part of this release. However, since this work was done during the 1.9.9 timeframe, it is mentioned here. Anyone who is interested may take a look at the
feature-pg-cbbranch here: https://gitlab.isc.org/isc-projects/kea/-/tree/feature-pg-cb. So far the only feature is the 7.0 schema, which is available in the
Deprecate Cassandra - Cassandra support is now deprecated. If you use it - don't panic. The only technical change for now is that Kea prints a warning about the feature being deprecated, but it otherwise functions as before. Cassandra code will remain intact in the remainder of the development 1.9.x and upcoming stable 2.0.x series. We are looking at removing it sometime during the development 2.1.x series. Version 2.2.x is foreseen to be the first stable branch with Cassandra support removed. This effectively means that users have well over a year to think about their migration strategy. There is a new Section
3.8 Deprecated Featuresin the ARM that discusses the technical and business reasons why we decided to deprecate Cassandra. Briefly, Cassandra's very different data model compared to other backends, namely MySQL and PostgreSQL, made it an ongoing maintenance and development challenge; some concepts simply could not be implemented as it was not the right tool to solve some DHCP problems. Also, there are many warning signs that the Cassandra project is having difficulties: packages for popular systems are not available, the C++ wrapper has a note about being in maintenance only for a while, the release versions of Cassandra require obsolete Python 2 (with Python 3 support being available in unreleased alpha versions of Cassandra), they don't work with Java 11 (and require outdated Java 8), and more. It was also by far the least popular backend.
For details on known issues, visit:
And for the list of issues marked as bugs:
The Kea project has a significant production deployment base with users who are looking for stability, rather than a constant stream of new "bleeding-edge" features. At the same time, we want to continue developing the software and add some new powerful, but difficult-to-implement, features. To meet these requirements we have both Stable and Development branches.
Stable releases are what you would expect: stable, released infrequently, without new features or significant changes, very well-tested. These can be identified by an even-numbered minor version number. The current stable release is 1.8.2. The older stable version of 1.6.3 is also available. If we discover important bugs that require fixing, we may release additional maintenance versions on the 1.8 branch, but that will be determined on a case-by-case basis. The next major stable version will be 2.0.0.
Development releases can be easily identified by an odd minor version number: for example, 1.9.0 is a development release. Subsequent releases on the same minor release branch get numbered with 1.9.1, 1.9.2, and so on.
Our goal is to make the development release available on the last Wednesday of each month. There may be exceptions (such as during holidays), but that's the general plan.
We encourage users to test the development releases and report back their findings.
For more details on the plan, see ISC's Software Support Policy at:
Kea is a DHCP implementation developed by Internet Systems Consortium 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 and DNS update servers, an example shell client to connect to the CA, a daemon that is able to retrieve YANG configuration and updates from Sysrepo, and a DHCP performance-measurement tool. Both DHCP servers 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 is stored in a CSV file by default; it can optionally be stored in a MySQL, PostgreSQL, or Cassandra (now deprecated) database instead. Host reservations can be stored in a configuration file, or in a MySQL, PostgreSQL, or Cassandra (now deprecated) database. They can also be retrieved from a RADIUS server, although this functionality is somewhat limited. Kea DHCPv4 and DHCPv6 daemons provide support for YANG models, which are stored in a Sysrepo datastore and can be configured via the NETCONF protocol.
This text references issue numbers. For more details, visit the Kea GitLab page at:
This version of Kea is released under the Mozilla Public License, version 2.0.
The premium and subscriber-only hooks libraries are provided in source code form, under the terms of an End User License Agreement (you will get the source code that you can modify freely, but you are not permitted to redistribute it).
Pre-built ISC packages for current versions of the most popular Linux operating systems are available at:
The Kea source and PGP signature for this release may be downloaded from:
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 (ARM). Documentation is included with the installation, at:
- or via https://kb.isc.org/docs/kea-administrator-reference-manual in HTML, plain text, or PDF formats
ISC maintains a public open source code tree, a wiki, an issue tracking system, milestone planning, and a roadmap at:
We ask 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 feedback on the Kea Users mailing list at:
We would also like to hear whether the documentation is adequate and accurate. Please open tickets in the Kea GitLab project for bugs, documentation omissions and errors, and enhancement requests. 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 development and maintenance are funded with support subscriptions. For more information on ISC's Kea and DHCP software support see:
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 on the Kea Users List:
Bugs and feature requests may be submitted via GitLab at:
The following summarizes changes since the previous release of 1.9.8:
In the core package
1920. [build] andrei Bump library versions for the Kea 1.9.9 development release. (Gitlab #1947) 1919. [bug] razvan Fix the run script hook library leaving behind defunct processes. (Gitlab #1878) 1918. [bug] razvan When parsed, PSID was incorrectly ignoring the PSID value when psid-len was 16 instead of ignoring it when the values is 0 as per the RFC. (Gitlab #1858) 1917. [func] tomek DHCPv4 and DHCPv6 are now more consistent when logging the reasons why a packet was dropped. This information is now available on debuglevel 15. Also added a section in the ARM discussing the debug levels. The subnet selection failed log message now provides more useful information about the subnet. (Gitlab #1915, #1916) 1916. [func] razvan The Kea DHCPv4 server accepts requests using server identifier configured at client class level. (Gitlab #1836) 1915. [func] andrei DOCSIS options are no longer offered to any vendor other than Cable Labs (vendor-id == 4491). This was not an explicit check previously and the match to the vendor relied on a technicality such that other vendors could have received these options under certain conditions. (Gitlab #1894) 1914. [func]* tomek The Cassandra (CQL) support is being deprecated, both for leases and host backends. For the time being the features will produce a warning, but will otherwise function normally. However, the functionality will be removed in the future Kea releases. (Gitlab #1892) 1913. [doc] tomek Kea adopted Developer Certificate of Origin for incoming contributions. Please see the CONTRIBUTING.md file for details. (Gitlab #1895) 1912. [doc] fdupont, tomek The Kea configuration syntax is now documented in BNF notation. See new appendix in the ARM. (Gitlab #504, #745) 1911. [bug] andrei Fixed a minor regression where kea-admin and keactrl would output technical errors like "unbound variable" instead of more helpful messages like "missing backend" because of the undefined variable checks introduced in 1.9.4. Added tests to further prevent it. (Gitlab #1653) 1910. [func] andrei Extended perfdhcp to send v4 DHCPRELEASE messages via -F flag. (Gitlab #1119) 1909. [build] fdupont Experimental support for Heimdal implementation of GSS-API with Kerberos 5 added. (Gitlab #1909) 1908. [func] razvan Added export for V4 option 82 (DHO_DHCP_AGENT_OPTIONS) and respective suboptions 1 (RAI_OPTION_AGENT_CIRCUIT_ID) and suboption 2 (RAI_OPTION_REMOTE_ID) in the run script hooks library. (Gitlab #1840) 1907. [doc] peterd, andrei, razvan Many Kea ARM corrections and updates. (Gitlab #1917) 1906. [func] fdupont Added support for the TKEY DNS resource record. (Gitlab #1880) 1905. [build] fdupont Added an optional --with-gssapi switch to the configure script. It checks for the presence and suitability of packages pertinent to GSS-TSIG. This has been added in anticipation of future work and does not add any functionality to Kea. (Gitlab #1884)
In the premium package
124. [bug] razvan Fix the forensic logging hook library leaving behind defunct processes when configured with prerotate and postrotate parameters. (Gitlab #1878) 123. [func] razvan The lease query hooks library accepts requests using server identifier configured at client class level. (Gitlab #1836) 122. [func]* tomek The Cassandra (CQL) support is being deprecated, for Forensic Logging log storage. For the time being the feature will produce a warning, but will otherwise function normally. However, the functionality will be removed in the future Kea releases. (Gitlab #1892) 121. [func] fdupont Created GSS-API C++ bindings for the new gss_tsig D2 hook library. (Gitlab #1909)
Thank you again to everyone who assisted us in making this release possible.
We look forward to receiving your feedback.