# Kea 1.6.0-beta, May 29 2019, Release Notes

Welcome to Kea 1.6.0-beta. 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, 
a daemon that is able to retrieve YANG configuration and updates from Sysrepo, 
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 is stored 
in a CSV file by default; it can optionally be stored in a MySQL, PostgreSQL, 
or Cassandra database instead. Host reservations can be stored in a 
configuration file; they can also be stored in a MySQL, PostgreSQL, or 
Cassandra database and, to some degree, retrieved from a RADIUS server. 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.

The text below references issue numbers. For more details, visit the Kea GitLab 
page at https://gitlab.isc.org/isc-projects/kea/issues. The major new features 
and changes in this version are:

1. **Config Backend**. Kea Configuration Backend (abbreviated as Config Backend 
or CB) is a new feature which lets the DHCPv4 and DHCPv6 servers manage and 
fetch their configuration from one or more MySQL databases. The MySQL CB 
implementation is distributed as a hooks library. You can now store most of the 
Kea configuration in the CB: global parameters, shared networks, subnets, 
pools, options, and option definitions. Instead of specifying these parameters 
in your local configuration, you can now put this information in the database 
and simply tell Kea where to find it. Kea will merge the parameters from the CB 
with other parameters configured locally (such as interfaces).  Kea can 
periodically poll the CB and retrieve updates. This will greatly simplify 
automated configuration change deployments.

The most basic configuration for CB looks more or less like this:

"Dhcp4": {
    "config-control": {
        "config-databases": [
            {
                "type": "mysql",
                "name": "kea",
                "user": "kea",
                "password": "iusedefaultpasswords",
                "host": "192.0.2.1"
            }
        ],
        "config-fetch-wait-time": 20
    },
    "hooks-libraries": [
        {
            "library": 
         "<kea_installation_path>/lib/kea/hooks/libdhcp_mysql_cb.so"
        }
    ],
   ...
}

The CB is supported for DHCPv4 and DHCPv6. The only database supported for now 
and the near future is MySQL.
You can connect multiple Kea instances to retrieve configurations from the same 
central database; this lets you effectively centralize your Kea servers' 
configuration and push configuration changes to all your Kea servers.

This 1.6.0-beta version supports only a single Kea configuration per 
configuration backend. During the beta period we will add server tags, where 
you will be able to specify that certain configuration elements (such as a 
specific subnet) should be applied only on servers with a matching server tag. 
This will let you differentiate configurations between servers while keeping 
all configuration elements in the same centralized database. In future releases 
(1.7.0 and beyond) we will continue improving and expanding this mechanism. The 
improvements will likely include adding more capabilities for configuration in 
database storage, such as client classes, hooks, logging, and network 
interfaces.

The CB is implemented for MySQL only. This is a conscious decision; we hope to 
polish the feature's rough edges on one specific backend before we implement it 
for other databases. It is somewhat likely that PostgreSQL will appear sometime 
in the future, but that will happen only when the MySQL-based CB is mostly 
complete. Unfortunately, due to Cassandra's nature as a non-relational database 
and the difficulty working with it, it is unlikely we will ever implement a CB 
for Cassandra.

The config backend is by far the most complex feature ever developed in Kea and 
we ask for your honest feedback on it. Did you manage to get it working? What 
was easy and what was difficult or not working? What are the features you'd 
like to see next?

2. **Management commands for the Config Backend**. The CB stores data in a 
MySQL schema that is public. It's possible to insert a configuration into the 
MySQL tables manually, or automatically using SQL scripts, but this requires a 
reasonably good knowledge of the schema. As an alternative, ISC has developed a 
new hook library that provides management commands for config backends. It 
simplifies many typical operations, such as listing, adding, retrieving, 
deleting of global parameters, shared networks, subnets, pools, options, and 
option definitions. For a complete list, see commands starting with "remote-" 
in [Appendix A of the Kea User's 
guide](https://ftp.isc.org/isc/kea/1.6.0-beta/doc/kea-guide.html#api). The 
cb_cmds hooks library is available to subscribers only. If you are not a 
subscriber and would like to participate in beta testing, please contact 
info@isc.org and our sales team will assist you.

3. **Native packages**. As we continue its development, Kea is adding 
integration with other open source products, including NETCONF (provided by 
Sysrepo), RADIUS (based on the FreeRADIUS client), and Cassandra. That 
flexibility comes at a price, though. It is getting more difficult to install 
Kea with those optional dependencies enabled. We also noticed that some OS 
distributions lag behind in packaging the latest Kea releases. To help 
alleviate both of those problems, ISC will start providing our own native (DEB 
and RPM) packages for several popular distributions. We are planning to provide 
packages for CentOS 7, Debian 9, Fedora 28 and 29, and Ubuntu 18.04, 18.10 and 
19.04. The binary packages will cover DHCPv4, DHCPv6, DDNS, Control Agent, 
NETCONF, and all three (MySQL, PostgreSQL, Cassandra) backends. ISC 
subscription customers will also be given an option to conveniently install 
hooks as separate packages. In the future we plan to experiment with packaging 
Sysrepo and all its necessary dependencies. The native packages will be 
available within four weeks after 1.6.0-beta sources become available; stay 
tuned for a separate announcement!

4. **Improved compatibility**. Kea follows RFC standards as defined by the 
IETF; however, there are some devices out there that are not as strict in 
following the standards. Nevertheless, Kea should be able to work with such 
devices. Kea 1.6.0 now sends the DHCPv4 message type as the first option 
(#530), the trailing null is now stripped from received options (#539), empty 
hostnames are handled better (#40), and it's now possible to define sub-options 
with codes 0 and 255 (#564).

5. **Control socket for DDNS**. The DDNS daemon has finally gotten its control 
socket and can process commands. It's now possible to update its configuration 
and in general interact with it while it's running. The following nine commands 
are now supported: build-report, config-get, config-reload, config-set, 
config-test, config-write, list-commands, shutdown, and version-get.

6. **Preliminary performance improvements**. While overall performance 
improvements will be the major focus of the next Kea release, we conducted some 
preliminary work in 1.6. Perfdhcp, a tool for testing performance, is now 
multi-threaded (#283) and has a new 'avalanche' mode to simulate a large number 
of devices renewing at once. It lets you measure how long it takes to provision 
a specified number of devices, with a realistic model of devices getting 
impatient and retransmitting when not provided with an answer within one 
second. Also, Kea DHCPv4 can now be configured to disable client-id lookup in a 
database to speed up operations (#509).

7. **Performance reports**. ISC has started publishing performance reports. The 
two documents available now are [Performance report comparing 1.4.0 and 
1.5.0](https://kb.isc.org/docs/kea-performance-tests-140-vs-150) and 
[Performance optimization 
suggestions](https://kb.isc.org/docs/kea-performance-optimization).

8. **New host cache commands**. Two new commands have been implemented in the 
host cache hook: cache-size (which lets you check the current number of cached 
entries) and cache-get-by-id (which lets you look up whether an entry for a 
specified hardware address, client-id, duid, circuit-id, or flex-id is in the 
cache) (#594).

9. **New subnet commands**. Two new commands were added to the subnet_cmds 
hook: subnet4-update and subnet6-update. They allow the existing IPv4 and IPv6 
subnets to be tweaked (#465). Previously in order to update an existing subnet 
you had to first remove it and then re-add it with the changes.

10. **New host commands**. Two new commands were added to the host_cmds hook. 
They allow retrieval of all reservations from a given subnet, either in one go 
(reservation-get-all) or page by page (reservation-get-page) (#313, 511).

11. **High Availability improvements**. Two improvements have been made in the 
High Availability code. First, it better handles abrupt time changes, e.g. when 
NTP changes the system clock (#599). Second, the CA daemon now adds Host http 
header, which makes it possible to set up a reverse HA proxy with NGINX (#360).

12. **Logging moved** to daemon scope (#273). Earlier Kea versions had the 
Logging scope defined at the global level in their JSON configurations, due to 
historical reasons that no longer apply. The idea was to have one configuration 
file shared by all daemons, but it didn't withstand the test of time. Kea 1.6.0 
moves the Logging entry to specific scopes, such as Dhcp4 or Dhcp6. For the 
time being, Kea 1.6.0 still accepts the old syntax, but prints a warning. 
Future Kea versions will eventually drop that backward compatibility and will 
produce an error. Make sure you update your configurations.

13. **Automatically calculate renewal and rebind timers** (#365). Earlier Kea 
versions had the renewal (t1) and rebind (t2) timers configured manually with 
their own defaults. These were simple mechanics that worked in general, but it 
was too easy to inadvertently misconfigure Kea. It is now possible to tell Kea 
to automatically calculate t1 and t2 times based on valid (v4) or preferred 
(v6) lifetimes. See the 'calculate-tee-times', 't1-percent', and 't2-percent' 
parameters for details.

14. **Hook libraries moved to separate directory**. Earlier Kea versions 
installed hooks in a /usr/lib/hooks/ directory. This was confusing as the 
/usr/lib/ directory is shared by all software installed on the system and it 
was unclear what the hooks meant. The directory is now called 
/usr/lib/kea/hooks. When upgrading to 1.6.0 make sure you update your 
configuration to point to the right hook libraries (#161).

15. **Hammer added**. ISC developed a tool that is used internally to build VMs 
and install Kea dependencies on many systems. We thought that, while the tool 
is not intended for end-users, there may be power users that could benefit from 
having access to such a tool. It is not part of the tarball release, but it may 
be retrieved from our GitLab repository (#373).

16. Many small **fixes related to recent OS releases**: NetBSD 8.0 (#165), 
Fedora 29 (#354), FreeBSD 11.2 (#367), CentOS 7 (#380), macOS/XCode (#561), 
Ubuntu 19.04 (#589), and installation on Debian 9 with MariaDB 10.1 (#389).

17. **RADIUS improvements**. RADIUS has gotten a round of improvements: a 
memory leak has been fixed (#415), accounting is now better documented (#416), 
and RADIUS with shared networks works much better (#474).

18. **Cassandra consistency** is now a configurable parameter (#16).

19. **Kea can recalculate statistics** when the server configuration changes 
(#394). This addresses a problem when statistics were reflecting an old 
configuration and didn't take into account configuration changes since the last 
full server reconfiguration.

20. **Better debugging of flex-id** for non-printable characters (#21).

This release includes TODO issues addressed since 1.5.0 (TODO in 1.6.0-beta and 
TODO in 1.6.0-final).

## License
Kea 1.6.0 is released under the Mozilla Public License, version 2.0.

   https://www.mozilla.org/en-US/MPL/2.0

The premium and subscriber-only hook 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).

## Testing premium and subscriber-only hooks

ISC Kea support customers will receive tickets inviting them to download the 
premium hooks, which are included with the support subscription. If you are 
interested in testing premium hooks and do not have a Kea support contract, 
please contact info at isc dot org to request a trial copy.

## Download

The Kea 1.6.0-beta source and PGP signature of the distribution may be 
downloaded from:

   https://www.isc.org/downloads

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

   https://www.isc.org/about/openpgp

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://kb.isc.org/docs/kea-administrator-reference-manual in HTML, plain text, 
or PDF formats.  ISC maintains a public open source code tree, wiki, issue 
tracking system, milestone planning, and a roadmap at 
https://gitlab.isc.org//isc-projects/kea.

Limitations and known issues with this release can be found at 
https://gitlab.isc.org/isc-projects/kea/wikis/known-issues-list.

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 feedback on 
the Kea User mailing list (https://lists.isc.org/mailman/listinfo/kea-users).  
Also we would 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.

## Support

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 Kea and DHCP software 
support see https://www.isc.org/support/.

Free best-effort support is provided by our user community via a mailing list. 
Information on all public email lists is available at 
https://www.isc.org/community/mailing-list. 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 GitLab at https://gitlab.isc.org/isc-projects/kea/issues.

## Changes

The following summarizes changes and important upgrade notes since the previous 
release (1.5.0).

1586.	[build]		razvan, marcin
	Bumped up libraries version numbers for Kea 1.6.0 beta release.
	(Gitlab #617,!340, git c0434bf882b6ec483120e39f6b70b5a40fe7c711)

1585.	[bug, func]		marcin
	MySQL Configuration Backend supports DHCPv6 interface-id parameter.
	(Gitlab #628,!341, git 3a07c636ba4c7fceabe59ec597c44a9c8e3367eb)

1584.	[doc]		marcin
	Documented Kea Configuration Backend in the Kea Administrator
	Reference Manual.
	(Gitlab #71,!314, git 3a65b7a9104f2a988dacf1acc26312b4259e958d)

1583.	[bug]		fdupont, marcin
	Corrected a bug which caused failures to merge a subnet from the
	Configuration Backend into the DHCP server's configuration
	when subnet identifier was modified.
	(Gitlab #492,!252, git c9aba2b5e915c27a8539e6b8f0498179ba896da4)

1582.	[bug]		tmark
	Input values for DHCPv4 and DHCPv6 options of type 'string'
	will now be trimmed of any trailing null bytes (0x0).
	(Gitlab #539, !330, git b126558e9e39e9bff517dceac25a00e96d150085)

1581.	[bug]		marcin
	Corrected a bug whereby the DHCPv6 server did not take into
	account a relay address specified at the shared network level
	during the subnet selection.
	(Gitlab #620,!332, git c2383e404a5227f6b55655c09ccdc03930815500)

1580.	[bug]		jonatan.raudsepp
	Compilation fix for Alpine linux in Perfdhcp code. Thanks to
	Jonatan Raudsepp for sending a patch!
	(Gitlab #624,!337, git 19321df9e4490b75ac7b322afec9d231bcb6ffe3)

1579.	[bug]		razvan
	Fixed a bug which caused setting dhcp4o6-port to not function via
	Kea configuration backend.
	(Gitlab #577,!331, git 98c24fe1873795bbc94d426c54c588b05d79406f)

1578.	[func]		fdupont
	The configuration syntax has changed. The Logging scope that used
	to be shared between all servers has been deprecated. Each daemon
	is supposed to define its own loggers using 'loggers' array. The
	old configuration syntax is still accepted, but is considered
	deprecated. Kea 1.6 will accept it, but that capability will be
	removed in the future. Please migrate your configuration to new
	syntax.
	(Gitlan #208,!196, git 37b8ec6c2c4b64681059f8fad26d112adbb7ee2b)

1577.	[func]		razvan
	Implemented host reservations page retrieval for Cassandra.
	(Gitlab #511,!278, git 152e82b49f5e5abd9d3a2a4825ed8620973f5ef1)

1576.	[doc]		fdupont
	New commands cache-get-by-id and cache-size are now documented.
	(Gitlab #594,!324, git 3753008cc77f71457b5d777560d8e36dc56e7acd)

1575.	[bug]		razvan
	Fixed issue with keactrl logging error when trying to stop running
	services.
	(Gitlab #534,!327, git 6ddee0a93ec4ad692cc385150c159d9e8da5232d)

1574.	[bug]		razvan
	Add logging to the MySQL config backend.
	(Gitlab #398,!315, git bc46fd3420afdf60ae8841866e8458f7f6e072e8)

1573.	[bug]		razvan
	Fixed build sysrepo from sources using sysrepo_config.
	(Gitlab #523,!262, git b86864a9b058a18eaaded2273dc5f40a9ec97c78)

1572.	[bug]		tmark
	Corrected an issue where kea-dhcp6 was incorrectly scheduling DNS
	entry removals when renewing leases with generated FQDNs.
	(Gitlab #577,!310, git 362f40bebbdbe083ec6420a43ee1c050edf6bba6)

1571.	[bug]		marcin
	The mysql_cb hooks library registers the MySQL backend for the
	DHCPv6 server.
	(Gitlab #603,!322, git 1ede298fcdc7a9b7018b6e300e2d759e33f73645)

1570.	[bug]		marcin
	Corrected the bug in the Kea HTTP library which could cause a server
	to assert when system clock was modified during the transaction.
	(Gitlab #599,!320, git 958abe5063b6e602c0070e336524e313c3a87671)

1569.	[perf]		fdupont
	Improved performance of the DHCPv4 server in cases when
	match-client-id set disabled by removing unnecessary query to the
	lease database."
	(Gitlab 509,!272, git 2ad41651c1118fe6f7dfb918df0694dd254706f1)

1568.	[bug]		tmark
	kea-dhcp6 now properly skips sanity checking prefix leases.
	Prior to this it was incorrectly subjecting them to sanity
	checks during memfile lease file reloads and then flagging
	the leases as incorrect.
	(Gitlab #591,!#313, git 12262c5df19673652be73cf1dd62d07527bee95d)

1567.	[bug]		marcin
	Kea HTTP client now always includes Host header in all HTTP requests.
	The Host header is required in all HTTP/1.1 requests. This corrects
	the problem whereby HA peers were unable to communicate via reverse
	HTTP proxy because the proxy was responding with Bad Request status
	when no Host header was included.
	(Gitlab #360,!305, git ddb6dbf4cf63e98d3954c5d46e0311abc4fd6cfc)

1566.	[func]		tmark
	kea-dhcp6 can now be configured to calculate values to
	send to clients for T1 and T2 times. Prior to this
	it was only possibly to specify explicit values.
	(Gitlab #365,!296, git 144b83a84c836d6ff17620b35cb74f830b13c2eb)

1565.	[func]		marcin
	MySQL Config Backend returns server tags associated with the
	configuration elements.
	(Gitlab #579,!309, git 1e2648df047fe964e8ad3e9deb1c85eea32b1219)

1564.	[func]		fdupont
	Implemented two new commands to manage subnets:	subnet4-update and
	subnet6-update. They allow an update of existing subnets
	configuration.
	(Gitlab #465,!265, git 71eb9188033f81dab56fc5a847a39f5497398b62)

1563.	[bug]		razvan
	Fixed compilation of google benchmarks.
	(Gitlab #520,!260, git 11aa890d30ecce5518b9f0bad389feea6be78167)

1562.	[bug]		marcin
	Corrected a bug whereby the DHCP server would trigger a segfault
	upon termination when MySQL configuration backend was in use.
	(Gitlab #571,!306, git 705e7bb6dd27ec90dd2807d4aac0905e3cb13de4)

1561.	[func]		tmark
	kea-dhcp6 now automatically deletes configuration elements
	that have been deleted from configuration backends.
	(Gitlab #566,!304, git 2e85376f1b57187b822c662144380e04372cffff)

1560.	[bug]		fdupont
	kea-dhcp4 now permits option code values of 0 and 255 for
	options defined in option spaces other than the "dhcp4" space.
	(Gitlab #564,!300, git 7a0a0b84d91893f08c0ee6f236daa05bede65166)

1559.	[func]		fdupont
	Added DHCPv6 support to the MySQL Config Backend hook.
	(Gitlab #397,!244, git 980091ecd717e41a61f0d7f6808213e450647d8e)

1558.	[func]		tmark
	In addition to a continuous string of digits, hexadecimal
	literals may now be a series of one or more octets separated
	by either colons or spaces.
	(Gitlab #484, git 251efcd5f518a215173845b22555276df0e0ffc6)

1557.	[bug]		marcin
	Added support for "reservation-mode" parameter in the shared network
	configuration parsers. It corrects a bug in Configuration Backend
	whereby host reservation mode was not stored in the database when
	specified via remote-network4-set command.
	(Gitlab #517,!301, git e6533001e9d850432254d3cfe995a4f7abcee6e2)

1556.	[bug]		fdupont
	Corrected parser for option definitions to refuse definitions with
	duplicate code or name.
	(Gitlab #503,!246, git 0befb653277463cd8f88740119fe90a93dbb1466)

1555.	[bug]		fdupont
	Corrected parsers for option definitions to prevent setting out of
	range option code values.
	(Gitlab #500,!247, git 5c139602d7656df74060fee63461ffba4f290547)

1554.	[func]		tmark
	kea-dhcp6 now uses globals, option definitions, options,
	share-networks, and subnets from configuration back ends.
	(Gitlab #413,!288, git ff367e273ed8763b354db272c5955a78203d865e)

1553.	[func]		marcin
	DHCPv4 server automatically fetches incremental configuration updates
	from the configuration backends.
	(Gitlab #103,!277, git 319f7709edb40d6c01390a34942b9d4a200b333e)
	(Gitlab #103,!289, git 80087e2d0f90f9ba6623860fed4f4d33ee935ad0)

1552.	[bug]		marcin
	Corrected inheritance of the subnet and shared network specific
	parameters in the MySQL Configuration Backend.
	(Gitlab #552,!295, git 4812e4227a57b29bfa3995e71588233424a3abb1)

1551.	[func]		razvan
	Added consistency and serial-consistency parameters to CQL
	connection. Fixed all statements.
	(Gitlab #16,!287, git 56a9b6a860899274f9cafe2366a6731a46490e92)

1550.	[func]		marcin
	Implemented inheritance of the DHCPv4 global and shared network
	specific configuration parameters when using configuration
	backend.
	(Gitlab #490,!284, git 2508f942e879ef74b20c07ffdba37d187d6ea932)

1549.	[func]		tmark
	kea-dhcp6 can now be configured to fetch data from configuration
	back ends. It does not yet utilize the data fetched.
	(Gitlab #104,!290, git d8a25c1ecd17ad24bdce6af19e7a42ce66d4c4f2)

1548.	[func]		razvan
	Added consistency and serial-consistency parameters to CQL
	connection.
	(Gitlab #16,!266, git 5771173d721464d879869fad6456211031858d6c)

1547.	[bug, doc]		fdupont
	Option value for sip-ua-cs-domains has been corrected in the
	Kea User's Guide. Thanks to Shawn Routhier from Infoblox for
	reporting this issue.
	(Gitlab #536,!281, git c128fd9a6b7bffc36ba4fe9a0badebe55441d673)

1546.	[func]		tmark
	kea-dhcp4 now uses options fetched from configured backends.
	(Gitlab #401,!254, git 6a33a6f1810f5899ff9c8bc79d0093eebad5c728)

1545.	[func]		fdupont
	A new parameter "data-directory" has been added to DHCPv6.
	If specified, it allows DHCPv6 server to store lease and
	server-id files in non-standard locations.
	(Gitlab #430,!263, git 1f094e18a21124abcaf846cab52c8cba65ca36bc)

1544.	[build]		fdupont
	Message compiler is no longer needed during compilation and
	generated message files are part of the distribution. They can be
	regenerated using --enable-generate-messages switch passed to
	configure script.
	(Gitlab #441,!233, git 499b7c36454bcac2553f7bf304d48d7d80f4d4ca)

1543.	[bug]		fdupont
	Corrected behavior of the remote-subnet4-set so as it is now
	possible to set the subnet using both an ID or a subnet prefix.
	(Gitlab #481,!251, git 9ef651950fde16e258e4b03dd21bbf6dd07d5231)

1542.	[test]		tmark
	MySQL, PostgreSQL, and CQL unit tests will now attempt to wipe
	the unit test data, rather than the (re)create the schema between
	each test.  This reduces test execution time appreciably.  The
	behavior may be overridden by defining environment variable:
	KEA_TEST_DB_WIPE_DATA_ONLY="false".  This will cause the schema
	to be recreated before each test but may dramatically increase
	test execution time.
	(Gitlab #526,!269, git 7e81d7bea27e919b652351880872aae68ad1b209)
	(Gitlab #531,!279, git 7f8c4fc535df3019789aea1881b7bb3bd539963a)

1541.	[bug]		fdupont
	Empty Relay Agent Information option is no longer sent in server
	responses. Thanks to Geoffrey Huang from Qingdao Agricultural
	University, and Jiaqi Liu from Qingdao WuKeSong Company
	Communication Limited, Shandong, PRC for reporting this issue.
	(Gitlab #519,#510,!271, git f3563396d2227e48e96a5d65587406d8d1868db5)

1540.	[func]		fdupont
	Added a new method deleteSharedNetworkSubnets4 in the config
	backend API to delete all subnets belonging to a shared network.
	(Gitlab #512,!256, git 76991c42d115641c7fdcd0f215137be578fb39a0)

1539.	[build]		fdupont
	Obsolete dns++.pc file for pkg-config was removed.
	(Gitlab #498,!274, git 93cd62c99f69cc379c08cd06791db522c1fb0aca)

1538.	[func]		marcin
	DHCP configuration parsers correctly handle unspecified parameters.
	This change was required for the MySQL Config Backend to record
	unspecified parameters as NULL in the database.
	(Gitlab #488,!259, git d3b33058651036be34200f16d2da230267415056)

1537.	[func]		godfryd
	Improved handling unix sockets in unit tests. Now by default
	they are created in temporary folder under /tmp folder. This
	fixes the issue with creating sockets with too long path
	in the case when source folder is deeply nested.
	(Gitlab #357,!258, git a45e2f68d7d1848adb0cf755954a3d76c9dff338)

1536.	[build]		tomek
	Many changes in keactrl, kea-admin, cql_config and sysrepo_config
	scripts. ISC is now using shellcheck to verify portability of
	our scripts.
	(Gitlab #480,!245, git 8818ba0260ba36710b88db6401069f9fe4f3a73a)

1535.	[func]		godfryd
	Added checking required Vagrant version by Hammer.
	Removed Hammer from EXTRA_DIST.
	(Gitlab #518,!257, git ea0006f6eb948d7d4a034b413c5086cbe483eb75)

1534.	[func]		marcin
	MySQL config backend correctly handles the optional values for
	subnets and shared networks. Also, updated the MySQL config
	backend to store and fetch T1 and T2 percentage settings.
	(Gitlab #489,!250, git 01fc4d5bb4105b90c7025e8ca8131c3c15203848)

1533.	[doc]		sgoldlust,stephen
	Kea User's Guide significantly updated.
	(Gitlab #362,!182, git 4b7a8df6054d18f2c90fe61d93533466f89e6324)

1532.	[func]*		marcin
	Renamed OptionalValue C++ object to Optional and modified its
	API. This object is now used to represent optional values in
	subnets and shared networks. This is an internal Kea logic
	change but it may impact existing user hooks libraries.
	(Gitlab #487,!232, git 1c58e0ce9b9fd6fc8864dbfb2335bc5841c78ff3)

1531.	[func]		tmark
	When fetching configuration data from configured backends,
	kea-dhcp4 will now merge option definitions.
	(Gitlab #400,!243, git 0c5d1417031e49bd0c247889989e187db2dd8f4b)

1530.	[bug]		adwol
	Potential syntax error in keactrl fixed. Thanks to Adam Osuchowski
	from Silesian University of Technology for providing a patch.
	(Gitlab #162,!241, git b1a1137f252432aa956ed6fea3da21c740857333)

1529.	[func]		tmark
	When fetching configuration data from configured backends,
	kea-dhcp4 will now merge global parameters.
	(Gitlab #402,!224, git dadaf76f8dd61b8bb3405aa5dc80029f09b2d4ec)

1528.	[func]		fdupont
	Aligned DHCPv4 and DHCPv6 specific tables used by the MySQL Config
	Backend. Extended MySQL schema to implement audit trail for the
	DHCPv6 Config Backend.
	(Gitlab #460,!232,!236, git 57f945f917db522773281c9e95ec8027afae6205)

1527.	[build]		adwol,fdupont,tomek
	Default Kea installation directory has been changed to
	${prefix}/lib/kea/hooks.
	(Gitlab #161,!240, git cfaf16cf02191bf5b7172cade3f58a626288b5f0)

1526.	[func]		tmark
	In addition to subnets, when fetching configuration data from
	configured backends, kea-dhcp4 will now merge shared-networks.
	(Gitlab #399,!215, git 6b57b6b5d678c91b6b380fbe08beafd06b0e7b1d)

1525.	[func]		fdupont
	Defined API for the DHCPv6 Configuration Backend.
	(Gitlab #458,!231, git f16e03d9bf1c10903c16b2614223b10880f73d50)

1524.	[func]		tomek
	Support for vendor options improved in DHCPv4 and DHCPv6. Kea is now
	able to send back vendor suboptions, even if the client packet didn't
	include DHCPv4 vivso (125) or DHCPv6 vendor (17) option. Usage of client
	classification in such a case is required, though.
	(Gitlab #464,!238, git 5c79da9358862657a631a9a8fc2ce79ae26b762e)

1523.	[bug]		fdupont
	IfaceMgr::send method now returns proper status that matches
	its documentation. Thanks to Matthias Stoeckl from Secunet
	for reporting this issue.
	(Gitlab #417,!221, git 4be58523f38097cea81ea06161aead58e00aeb2a)

1522.	[bug]		marcin
	The "unspecified" DHCP timer values (e.g. renew-timer) are
	represented as NULL values in the database. This corrects
	a bug whereby the unspecified timers defaulted to 0 which
	prevented the DHCP server from calculating the timers to
	be sent to the client. Instead a value of 0 was sent.
	(Gitlab #451,!227, git 5ec9a55528fbcfff4e0c808f9a745b9fd3a5dfae)

1521.	[func]		marcin
	Removed subsecond precision for the timestamps in MySQL config
	backend. It caused issues on systems with MySQL version prior
	to 5.6.4 which don't support subsecond timestamp values.
	(Gitlab #444,!229, git 71200e98f5a862908240a0d2e269b5da23290af9)

1520.	[build]		fdupont
	Made perfdhcp build optional and off by default: to build it
	please use the new --enable-perfdhcp configure flag.
	(Gitlab #340,!220, git b2d9a5559c348e82d6730809ccf1429097a9872c)

1519.	[bug]		Brent Bloxam
	A bug in kea-admin that always assumed the PostgreSQL database is
	always local has been fixed. Thank you to Brent Bloxam from
	Beanfield Metroconnect for submitting a patch!
	(Gitlab #423,!216, git d14e2f34c7d544aeb5e1e219f305fac9ab18c498)

1518.	[func]		marcin
	Extended MySQL schema to include the types of the global DHCP
	parameters in the database. The Kea servers will use this
	information to cast the values fetched from the database into
	their actual types. The supported types are: string, integer,
	boolean and real.
	(Gitlab #429,!217, git edd745c507ce5a888461df1489311de0c22cd312)

1517.	[func]		tmark
	kea-dhcp4 will now connect to and fetch configuration data from
	configured backends. At this point, only fetched subnet data is
	merged and used.
	(Gitlab #101,!202, git c572f8aea94349ff5fb4afee13a88ba811cc6459)

1516.	[func]		marcin
	Implemented audit trail for MySQL Configuration Backend. It allows
	for tracking incremental changes in the servers' configurations.
	Both mysql_cb hooks library and the MySQL schema have been updated
	to facilitate this feature.
	(Gitlab #396,!205, git 6d40db07ef641eef29405c42e718979e7a1e8675)

1515.	[func]		fdupont
	Changes required for new host commands that retrieve all host
	reservations from a given subnet (reservation-get-all,
	reservation-get-page) added. Also added documentation.
	(Gitlab #313,!199, git 991b2fadcb9e8171a78e27f95e4bfba6393d7824)

1514.	[func]		fdupont
	Control Agent and DHCP-DDNS daemons now support config-reload
	command, that instruct a given server to load again its
	configuration from a file on disk.
	(Gitlab #375,!192, git 93648a3a4918225e2c4413ae220fccc59eaea99a)

1513.	[func]		godfryd
	Fixed perfdhcp that now it keeps requested rate during performance
	testing. Previously it was always about 20% lower than expected.
	(Gitlab #283,!135, git 329f54bb151ec35888e9a8070cc5fa368d6f1f5e)

1512.   [func]      tmark
	kea-dhcp4 will now ignore empty Host Name (option code 12) values
	received from clients. While an empty value for this option is
	not RFC-compliant, some clients do send them. Prior to the this
	server would drop the entire packet. In the spirit of being liberal
	in what we accept, the server will now simply omit the option.
	(Gitlab #40,!203, git f41bd35c3e7a3bdc1f31c5602fd91d5c84c60163)

1511.	[func]		fdupont
	Obsolete experimental secure DHCPv6 options (701-704) removed.
	(Gitlab #386,!196, git 1114527652615fb730e323946cafaf1c7ca72b42)

1510.	[bug]		fdupont
	DHCPv4 and DHCPv6 no longer crash if badly broken configuration
	is received.
	(Gitlab #381,!193, git f45fe7b7e3916d36d017b4ec5b50588fbf517d86)

1509.	[func]		tmark
	kea-dhcp4 can now be configured to calculate values to
	send to clients for for T1 and T2 (options 58 and 59
	repsectively). Prior to this it was only possible to
	specify explicit values.
	(Gitlab #365,!194, git 67944844a40436cd69e0e5b4962f5c9cba89ef6f)

1508.	[func]		fdupont
	Implemented the management API using a control socket for the
	DHCP DDNS (D2) server. D2 now supports the following commands:
	build-report, config-get, config-set, config-test, config-write,
	list-commands, shutdown and version-get. Also, extended Control
	Agent (CA) to support one additional command: config-set.
	(Gitlab #30,!183, git ab27550cec365f42289eb5fa1bc39f33f01b19c2)

1507.	[func]		tmark
	kea-dhcp4 now ensures that the message type option (53) is
	the first option in outbound DHCPv4 packets. This was done
	to accommodate non-compliant clients that require the option
	to be first.
	(Gitlab #363,!177, git 34f40035bf7a7849083138cacee440a9f0991d67)

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.

We look forward to receiving your feedback.