[Kea-users] DDNS doesn't update local zone

Alessandro Vesely vesely at tana.it
Wed Nov 12 13:03:04 UTC 2025


Hi Darren,

I switched to filenames.  Now the logs are clear enough to allow fixing the 
forward- and reverse- ddns settings.  (It seems it has been working for months 
just because nobody happened to get a different IP than the time before.)


Thanks a lot
Ale


On Tue 11/Nov/2025 19:34:47 +0100 Darren Ankney wrote:
> Hi Ale,
> 
> Your loggers section indicates that there should be a large amount of
> information heading to syslog.  I believe you are encountering this:
> https://gitlab.isc.org/isc-projects/kea/-/issues/3921 whose fix was
> backported to 2.6.4 here:
> https://gitlab.isc.org/isc-projects/kea/-/issues/3992
> 
> Thank you,
> Darren Ankney
> 
> On Tue, Nov 11, 2025 at 11:49 AM Alessandro Vesely <vesely at tana.it> wrote:
>>
>> Hi Darren,
>>
>> thanks for taking care.
>>
>> One day after, all the other three clients have renewed (I can see the updated expire time in dhcp4.csv[.2].)  All I have in the logs is this:
>>
>> Nov 10 12:08:17 190 north kea-dhcp-ddns: INFO  [kea-dhcp-ddns.dctl.140480598193344] DCTL_STARTING DhcpDdns starting, pid: 15727, version: 2.6.3 (stable)
>> Nov 10 12:23:45 190 north kea-dhcp4: INFO  [kea-dhcp4.dhcp4.140607992743872] DHCP4_STARTING Kea DHCPv4 server version 2.6.3 (stable) starting
>> Nov 10 12:23:45 190 north kea-dhcp4: INFO  [kea-dhcp4.commands.140607992743872] COMMAND_RECEIVED Received command 'config-set'
>> Nov 10 12:24:55 190 north kea-dhcp4: INFO  [kea-dhcp4.dhcp4.140458599126976] DHCP4_STARTING Kea DHCPv4 server version 2.6.3 (stable) starting
>> Nov 10 12:24:55 190 north kea-dhcp4: INFO  [kea-dhcp4.commands.140458599126976] COMMAND_RECEIVED Received command 'config-set'
>> Nov 10 12:25:45 190 north kea-dhcp4: INFO  [kea-dhcp4.dhcp4.140267918301120] DHCP4_STARTING Kea DHCPv4 server version 2.6.3 (stable) starting
>> Nov 10 12:25:45 190 north kea-dhcp4: INFO  [kea-dhcp4.commands.140267918301120] COMMAND_RECEIVED Received command 'config-set'
>> Nov 10 12:47:54 190 north kea-dhcp-ddns: INFO  [kea-dhcp-ddns.dctl.140298412311744] DCTL_STARTING DhcpDdns starting, pid: 17117, version: 2.6.3 (stable)
>>
>> DHCP dialog, as shown by dhcpdum running on the server, looks fine.
>>
>> Both commands are running with option -c <their config file>.  The logging section for one:
>>
>>                 "loggers":
>>                 [
>>                         {
>>                                 // This section affects kea-dhcp4, which is the base logger for DHCPv4
>>                                 // component. It tells DHCPv4 server to write all log messages (on
>>                                 // severity INFO or more) to a file.
>>                                 "name": "kea-dhcp4",
>>                                 "output_options":
>>                                 [
>>                                         {
>>                                                 "output": "syslog:local7",
>>
>>                                                 // Default is "%-5p [%c.%t] %m\n";
>>                                                 // %-5p The severity of the message
>>                                                 // %c The log source. This includes two elements: kea-dhcp4 and library.
>>                                                 // %i The process ID.
>>                                                 // %t The thread ID.
>>                                                 // %m The log message itself.
>>
>>                                                 "pattern": "%m\n",
>>
>>                                                 // This governs whether the log output is flushed to disk after
>>                                                 // every write.  The default is true (?)
>>                                                 "flush": false
>>
>>                                                 // This specifies the maximum size of the file before it is
>>                                                 // rotated.
>>                                                 // "maxsize": 1048576,
>>
>>                                                 // This specifies the maximum number of rotated files to keep.
>>                                                 // "maxver": 8
>>                                         }
>>                                 ],
>>                                 // This specifies the severity of log messages to keep. Supported values
>>                                 // are: FATAL, ERROR, WARN, INFO, DEBUG
>>                                 "severity": "DEBUG",
>>
>>                                 // If DEBUG level is specified, this value is used. 0 is least verbose,
>>                                 // 99 is most verbose. If severity for the logger is not DEBUG, this
>>                                 // value is ignored.
>>                                 "debuglevel": 99
>>                         }
>>                 ]
>>
>> For the other:
>>
>>    "loggers": [
>>      {
>>          // This specifies the logging for D2 (DHCP-DDNS) daemon.
>>          "name": "kea-dhcp-ddns",
>>          "output-options": [
>>              {
>>                  // Specifies the output file. There are several special values
>>                  // supported:
>>                  // - stdout (prints on standard output)
>>                  // - stderr (prints on standard error)
>>                  // - syslog (logs to syslog)
>>                  // - syslog:name (logs to syslog using specified name)
>>                  // Any other value is considered a name of the file
>>                  "output": "syslog:local7",
>>
>>                  // Shorter log pattern suitable for use with systemd,
>>                  // avoids redundant information
>>                  "pattern": "%m\n"
>>
>>                  // This governs whether the log output is flushed to disk after
>>                  // every write.
>>                  // "flush": false,
>>
>>                  // This specifies the maximum size of the file before it is
>>                  // rotated.
>>                  // "maxsize": 1048576,
>>
>>                  // This specifies the maximum number of rotated files to keep.
>>                  // "maxver": 8
>>              }
>>          ],
>>          // This specifies the severity of log messages to keep. Supported values
>>          // are: FATAL, ERROR, WARN, INFO, DEBUG
>>          "severity": "DEBUG",
>>
>>          // If DEBUG level is specified, this value is used. 0 is least verbose,
>>          // 99 is most verbose. Be cautious, Kea can generate lots and lots
>>          // of logs if told to do so.
>>          "debuglevel": 99
>>      }
>>    ]
>>
>>
>> One strange thing is their opening the lockfile many times:
>>
>> 818-north:/# for p in $(pgrep -u _kea); do lsof -p $p | grep lockfile; done
>> kea-dhcp4 21436 _kea   3u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea   4u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea   5u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea   6u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea  21u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea  22u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea  23u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea  24u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp4 21436 _kea  25u      REG     0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp- 21479 _kea   3u      REG               0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp- 21479 _kea   4u      REG               0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp- 21479 _kea   6u      REG               0,25        0        6 /run/lock/kea/logger_lockfile
>> kea-dhcp- 21479 _kea  14u      REG               0,25        0        6 /run/lock/kea/logger_lockfile
>>
>>
>> What else can I test?
>>
>>
>> Best
>> Ale
>>
>>
>> On Tue 11/Nov/2025 13:11:03 +0100 Darren Ankney wrote:
>> > Hi Ale,
>> >
>> > As a sanity check, is Kea logging other clients messages as expected
>> > if you release and renew?
>> >
>> > Thank you,
>> > Darren Ankney
>> >
>> > On Mon, Nov 10, 2025 at 7:08 AM Alessandro Vesely <vesely at tana.it> wrote:
>> >>
>> >> Hi,
>> >> I recently upgraded to Devuan Excalibur, equivalent to Debian Trixie, and had
>> >> some difficulty starting the Kea daemons. Now they're running.  However, a
>> >> client somehow got a different IP than it had before.
>> >>
>> >> The host name and PTR records still use the previous IP.
>> >>
>> >> I tried to fix it by issuing dhclient -r/ dhclient.  As a result, I have
>> >> several records showing the new IP in /var/lib/dhcp4.csv, but the DNS records
>> >> are unchanged.
>> >>
>> >> In kea-dhcp4 both enable-updates and ddns-send-updates are set to true.
>> >>
>> >> In both kea-dhcp4.conf and kea-dhcp-ddns.conf I set debuglevel to 99, but, upon
>> >> restarting, I only got the two lines
>> >>
>> >> kea-dhcp4: INFO  [kea-dhcp4.commands.140267918301120] COMMAND_RECEIVED Received
>> >> command 'config-set'
>> >>
>> >> and
>> >>
>> >> kea-dhcp-ddns: INFO  [kea-dhcp-ddns.dctl.140298412311744] DCTL_STARTING
>> >> DhcpDdns starting, pid: 17117, version: 2.6.3 (stable)
>> >>
>> >>
>> >>
>> >> Dhcp releases and subsequent discover, offer, request and ack are not logged.
>> >>
>> >>
>> >> Is there a way to force the DNS to sync?
>> >>
>> >>
>> >> Best
>> >> Ale
>> >> --
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> --
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>> >>
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>>
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