[Kea-users] Kea-DHCP4 exiting right after start

Sun Mar 15 12:08:40 UTC 2026

Thanks a lot Doug and Darren.  I've set both settings.

Best
Ale

On Sat 14/Mar/2026 14:18:27 +0100 Darren Ankney wrote:
> Hi Ale,
> 
> If what Doug has said is not possible in your environment, there may
> be a solution provided in Kea:
> https://kea.readthedocs.io/en/kea-2.6.3/arm/dhcp4-srv.html#interface-configuration
> mentions "service-sockets-max-retries" which is 0 by default but can
> be set to a positive integer which should make Kea retry for the
> specified amount of times with "service-sockets-retry-wait-time"
> between tries (default 5000ms).
> 
> Thank you,
> Darren Ankney
> 
> On Fri, Mar 13, 2026 at 6:49 PM Doug Freed <dwfreed at isc.org> wrote:
>>
>> On 3/13/26 12:47, Alessandro Vesely wrote:
>> > Hi,
>> >
>> > when the server boots, it starts DNS in this order:
>> >
>> > ...
>> > lrwxrwxrwx 1 root root 19 Jun 28  2019 S03mynetwork -> ../init.d/mynetwork
>> > lrwxrwxrwx 1 root root 19 Jul 10  2020 S03rmnologin -> ../init.d/rmnologin
>> > lrwxrwxrwx 1 root root 26 Oct 18  2021 S03rng-tools-debian -> ../init.d/
>> > rng-tools-debian
>> > lrwxrwxrwx 1 root root 17 Nov  7 12:59 S04elogind -> ../init.d/elogind
>> > lrwxrwxrwx 1 root root 26 Nov  7 12:59 S04kea-dhcp4-server -> ../init.d/
>> > kea-dhcp4-server
>> > lrwxrwxrwx 1 root root 30 Nov  7 12:59 S04kea-dhcp-ddns-server -> ../
>> > init.d/kea-dhcp-ddns-server
>> > lrwxrwxrwx 1 root root 15 Nov  7 12:59 S04named -> ../init.d/named
>> > ...
>> >
>> > However, upon login I find no DHCP4.  The log says so:
>> >
>> > Mar 13 17:48:43 INFO  DHCP4_CONFIG_COMPLETE DHCPv4 server has completed
>> > configuration: added IPv4 subnets: 1; DDNS: enabled
>> > Mar 13 17:48:43 INFO  DHCPSRV_MEMFILE_DB opening memory file lease
>> > database: name=/var/lib/kea/dhcp4.csv persist=true type=memfile universe=4
>> > Mar 13 17:48:43 INFO  DHCPSRV_MEMFILE_LEASE_FILE_LOAD loading leases
>> > from file /var/lib/kea/dhcp4.csv.2
>> > Mar 13 17:48:43 INFO  DHCPSRV_MEMFILE_LEASE_FILE_LOAD loading leases
>> > from file /var/lib/kea/dhcp4.csv
>> > Mar 13 17:48:43 INFO  DHCPSRV_MEMFILE_EXTRACT_EXTENDED_INFO4 extracting
>> > extended info saw 8 leases, extended info sanity checks modified 0 /
>> > updated 0 leases and 0 leases have relay or remote id
>> > Mar 13 17:48:43 INFO  DHCPSRV_MEMFILE_LFC_SETUP setting up the Lease
>> > File Cleanup interval to 3600 sec
>> > Mar 13 17:48:43 INFO  DHCPSRV_DHCP_DDNS_SENDER_STARTED NameChangeRequest
>> > sender has been started: enable_updates: yes, server-ip: 127.0.0.1,
>> > server-port: 53001, sender-ip: 0.0.0.0, sender-port: 0, max-queue-size:
>> > 1024, ncr-protocol: UDP, ncr-format: JSON
>> > Mar 13 17:48:43 WARN  DHCPSRV_OPEN_SOCKET_FAIL failed to open socket:
>> > the interface eth2r is not running
>> > Mar 13 17:48:43 INFO  DHCP4_OPEN_SOCKETS_FAILED maximum number of open
>> > service sockets attempts: 0, has been exhausted without success
>> > Mar 13 17:48:43 WARN  DHCPSRV_NO_SOCKETS_OPEN no interface configured to
>> > listen to DHCP traffic
>> > Mar 13 17:48:43 INFO  DHCPSRV_CFGMGR_USE_ALLOCATOR using the iterative
>> > allocator for V4 leases in subnet 172.25.197.0/24
>> > Mar 13 17:48:43 WARN  DHCP4_MULTI_THREADING_INFO enabled: yes, number of
>> > threads: 8, queue size: 64
>> > Mar 13 17:48:43 INFO  DHCP4_STARTED Kea DHCPv4 server version 2.6.3 started
>> > Mar 13 17:48:43 INFO  DHCP4_SHUTDOWN server shutdown
>> >
>> >
>> > S03mynetwork contains a line saying `ip link set eth2r up`.  Indeed,
>> > when S04named came up, it logged:
>> >
>> > ...
>> > Mar 13 17:48:43 30 north named[2073]: listening on IPv4 interface eth2r,
>> > 172.25.197.1#53
>> > Mar 13 17:48:43 30 north named[2073]: listening on IPv6 interface eth2r,
>> > 2a02:29e1:500:6c22::1#53
>> > ...
>> >
>> > Should I change the init order?  Put a pause?  What else?
>> >
>> > TIA for any hint
>> > Best
>> > Ale
>>
>> "The interface eth2r is not running" means the interface does not have
>> the "RUNNING" flag, which generally indicates whether the interface is
>> actually operational and capable of being used for traffic.  Your
>> network script should wait until /sys/class/net/eth2r/operstate contains
>> "up" before finishing to ensure that everything is operational.
>> Typically this happens rather quickly, but if something like 802.1x is
>> involved, it can be a non-zero amount of time waiting for 802.1x to
>> complete.  You may want to reorder operations if there are multiple
>> interfaces so that 'ip link set eth2r up' is run as early as possible,
>> as well any 802.1x auth, so it has time to get the RUNNING flag while
>> other operations are being performed before the script completes, so it
>> can spend less time waiting for operstate to change.
>>
>> -Doug
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