Hi Christoph,
Looking at your configuration, I note that there are no dynamic pools.
I notice your client is reserved address fd00:192:168:3::3 I further
notice that there is no prefix delegation configured and none reserved
for the client. The log messages of
ALLOC_ENGINE_V6_ALLOC_NO_LEASES_HR correspond to the client asking for
a prefix delegation (IA_PD) but not receiving one as noted in the logs
here:
msg_type=SOLICIT (1), trans_id=0xaeccc3,
options:
[...]
type=00025(IA_PD), len=00012: iaid=1448103320, t1=0, t2=0
and in the response:
msg_type=ADVERTISE (2), trans_id=0xaeccc3,
[...]
type=00025(IA_PD), len=00056: iaid=1448103320, t1=0, t2=0,
options:
type=00013, len=00040: NoPrefixAvail(6) "Sorry, no prefixes could
be allocated."
The reservation is clearly used for the IA_NA (fd00:192:168:3::3) or
the client would not receive an IP address at all.
As far as the failure of hostname, that is a separate issue.
According to your ddns settings, you should be replacing the hostname
supplied by the client and it should use the one found in your
reservation. You said it eventually obtains the correct hostname. Can
you send the logs showing this?
Thank you,
Darren Ankney
On Mon, Dec 1, 2025 at 5:27 PM Christoph Markert <[email protected]> wrote:
>
> Hi Darren,
>
> please find my configuration below:
> {
>
> "Dhcp6":
> {
> "dhcp-ddns": {
> "enable-updates": true
> },
> "ddns-replace-client-name": "always",
> "ddns-generated-prefix": "v6",
> "ddns-qualifying-suffix": "local.markert.live",
> "ddns-override-client-update": true,
> "ddns-override-no-update": true,
>
> "hostname-char-set": "[^A-Za-z0-9.-]",
> "hostname-char-replacement": "x",
> "client-classes": [
> {
> "name": "Default",
> "test": "not (option[1].hex == '0x00020000AB11D087EFD048F95BBD')",
> "option-data":
> [
> {
> "name": "dns-servers",
> "data": "fd00:192:168:3::1"
> },
> {
> "name": "domain-search",
> "data": "local.markert.live"
> }
> ]
> }
> ],
> "loggers": [
> {
> "name": "kea-dhcp6",
> "severity": "DEBUG",
> "debuglevel": 99,
> "output_options": [
> {
> "output": "kea-dhcp6.log",
> "maxver": 10
> }
> ]
> },
> {
> "name": "kea-dhcp6.dhcpsrv",
> "severity": "DEBUG",
> "debuglevel": 99,
> "output_options": [
> {
> "output": "dhcp6-dhcpsrv.log",
> "maxver": 10
> }
> ]
> },
>
> {
> "name": "kea-dhcp6.leases",
> "severity": "DEBUG",
> "debuglevel": 99,
> "output_options": [
> {
> "output": "dhcp6-leases.log",
> "maxver": 10
> }
> ]
> }
> ],
> "interfaces-config":
> {
> "interfaces": ["enp2s0"], // This is the internal interface
> "service-sockets-max-retries": 10,
> "service-sockets-retry-wait-time": 3000
> },
> "lease-database":
> {
> "type": "memfile",
> "persist": true,
> "name": "kea-leases6.csv",
> "lfc-interval": 3600
> },
>
> "renew-timer": 15840,
> "rebind-timer": 27720,
> "valid-lifetime": 31680,
> "shared-networks":
> [
> {
> # Name of the shared network. It may be an arbitrary string
> # and it must be unique among all shared networks.
> "name": "markert-live-local",
>
> # The subnet selector can be specified at the shared-network level.
> # Subnets from this shared network will be selected for directly
> # connected clients sending requests to the server's "enp2s0" interface.
> "interface": "enp2s0",
>
> # This starts a list of subnets in this shared network.
> # There are two subnets in this example.
> "subnet6":
> [
>
> {
> // Internal ID to identify subnet internally
> "id": 19216810,
> // Subnet for fd00:192:168:0::/48 - static IPs (usable host IP range:
> fd00:192:168:0::1 - fd00:192:168:0::ffff)
> "subnet": "fd00:192:168:0::/48",
> // Add DHCP IPv6 Pool
> "pools":
> [ ],
> // Add reservations here for subnet
> "reservations":
> [
> {
> "duid": "00:02:00:00:ab:11:d0:87:ef:d0:48:f9:5b:bd",
> "ip-addresses": [ "fd00:192:168:0::1" ],
> "hostname": "v6-vmhomeserver"
> }
> ],
> // Additional information for subnet
> "option-data":
> [
> {
> "name": "dns-servers",
> "data": "fd00:192:168:3::1"
> },
> {
> "name": "domain-search",
> "data": "local.markert.live"
> }
> ]
> },
> {
> "id": 1921681,
> // Subnet for fd00:192:168:1::/48 - static IPs (usable host IP range:
> fd00:192:168:1::1 - fd00:192:168:1::ffff)
> "subnet": "fd00:192:168:1::/48",
> "client-class": "Default",
> // Add DHCP IPv6 Pool
> "pools":
> [ ],
> // Add reservations here for subnet
> "reservations":
> [
> {
> "hw-address": "52:54:00:74:f6:13",
> "ip-addresses": [ "fd00:192:168:1::1" ],
> "hostname": "v6-vmhomeserver"
> }
> ]
> },
> {
> "id": 1921682,
> // Subnet for fd00:192:168:2::/48 - static IPs (usable host IP range:
> fd00:192:168:2::1 - fd00:192:168:2::ffff)
> "subnet": "fd00:192:168:2::/48",
> "client-class": "Default",
> // Add DHCP IPv6 Pool
> "pools":
> [ ],
> // Add reservations here for subnet
> "reservations":
> [
> {
> "hw-address": "52:54:00:74:f6:13",
> "ip-addresses": [ "fd00:192:168:2::1" ],
> "hostname": "v6-vmhomeserver"
> }
> ]
> // Additional information for subnet
> //"option-data":
> },
> {
> "id": 1921683,
> // Subnet for fd00:192:168:3::/48 - static IPs (usable host IP range:
> fd00:192:168:3::1 - fd00:192:168:3::ffff)
> "subnet": "fd00:192:168:3::/48",
> "client-class": "Default",
> // Add DHCP IPv6 Pool
> "pools":
> [ ],
> // Add reservations here for subnet
> "reservations":
> [
>
> {
> "hw-address": "52:54:00:74:f6:13",
> "ip-addresses": [ "fd00:192:168:3::1" ],
> "hostname": "v6-vmhomeserver"
> },
> {
> "duid": "00:04:71:7d:ec:24:45:86:f2:f8:07:fd:6a:c2:53:b6:be:da",
> "ip-addresses": [ "fd00:192:168:3::2" ],
> "hostname": "v6-homeserver"
> },
> // VMDatabaseServer
> {
> //"hw-address": "52:54:00:ef:57:d9",
> "duid": "00:03:00:01:52:54:00:ef:57:d9",
> "ip-addresses": [ "fd00:192:168:3::3" ],
> "hostname": "v6-vmdatabaseserver"
> //"option-data":
> },
> // VMHomeHub
> {
> //"hw-address": "52:54:00:ed:13:86",
> "duid": "00:03:00:01:52:54:00:ed:13:86",
> "ip-addresses": [ "fd00:192:168:3::4" ],
> "hostname": "v6-vmhomehub"
> //"option-data":
> }
> ]
> // Additional information for subnet
> //"option-data":
> },
> {
> "id": 19216816,
> "subnet": "fd00:192:168:f::/48",
> "client-class": "Default",
> "pools":
> [
> {
> "pool": "fd00:192:168:f::5-fd00:192:168:f::ffff"
> }
> ],
> // Add reservations here for subnet
> "reservations":
> [
> // VMHomeServer - interface 'enp2s0'
> {
> "hw-address": "52:54:00:74:f6:13",
> "ip-addresses": [ "fd00:192:0168:f::1" ],
> "hostname": "v6-vmhomeserver"
> //"option-data":
> }
> ]
> // Additional information for subnet
> //"option-data":
> }
> ]
> }
> ]
> # end of shared-networks
> }
> }
>
>
> However, after a few hours the right host name is assigned again, so that is
> strange. It seems to happen primarily after Debian updates on 'homehub' and
> 'databaseserver' (and occasionally restarts of those)
>
> Best,
> C.
>
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