New IP address after each reboot

Mon Apr 25 23:51:38 UTC 2022

Hi Jean-Philippe

Are your clients using random mac addresses? if so then each time they 
reboot they get a different mac address, and to the server it looks like 
a new client. My guess is the client-id stays the same? Can you use the 
client ID in the reservation setup rather than hwaddr?

regards,

Glenn

On 2022-04-26 08:21, Jean-Philippe Martin wrote:

> Hi
> 
> We use kea 2.01 (lease and reservation in mysql)
> 
> I have exactly this problem :
> 
> if i use a subnet with "match-client-id": false
> 
> my reservation (identifier is hwaddr) work but other lease is a newer 
> ip at each reboot
> 
> If i use a subnet with "match-client-id": true
> 
> lease d'ont be reset at boot but reservation don't work any more
> 
> best regards
> 
> _________________________________________
> Hi Anton,
> 
> Have you considered dropping the DHCPRELEASE packets instead?
> 
> You can read how this could be done in Gitlab #606 "Drop packets in 
> DROP class" at https://gitlab.isc.org/isc-projects/kea/-/issues/606
> 
> Please refer to the Kea Arm for a discussion on the "DROP" class.
> 
> Kind Regards Peter
> 
> ________________________________
> From: Kea-users <kea-users-bounces at lists.isc.org> on behalf of Anton 
> Starikov <starikov.a at tecomgroup.ru>
> Sent: 18 October 2020 19:02
> To: kea-users at lists.isc.org <kea-users at lists.isc.org>
> Subject: [Kea-users] New IP address after each reboot
> 
> Good afternoon!
> 
> Sorry for my english.
> 
> There is a problem with Kea Dhcp4 1.6.3 (1.8 is the same).
> 
> After each reboot, the client (Ubuntu, Arch) gets a new ip address from 
> KeaDhcp. As I understand it, this is due to the fact that Kea, after 
> receiving DHCPRELEASE from the client, does not immediately release the 
> address (although it adds a line with expire = 0 to the 
> lease-database), but does it after a while.
> 
> As an experiment, I limited the address pool to two ip. And with each 
> reboot (interval ~ 20 seconds), the client received different addresses 
> in a circle.
> 
> Previously, Mikrotik was used as DHCP, there was no such problem. The 
> client rebooted and, if the address was still free, he received it 
> back.
> 
> Is there any way to force Kea to immediately release such addresses?
> 
> I tried to change the settings described in the documentation in 
> section "10. Lease Expiration", it didn't help.
> 
> {
> 
> "Dhcp4": {
> 
> "loggers": [
> 
> {
> 
> "name": "kea-dhcp4",
> 
> "output_options": [
> 
> {
> 
> "output": "/var/log/kea-debug.log",
> 
> "maxver": 8,
> 
> "maxsize": 204800,
> 
> "flush": true,
> 
> "pattern": "%d{%j %H:%M:%S.%q} %c %m\n"
> 
> }
> 
> ],
> 
> "severity": "DEBUG",
> 
> "debuglevel": 99
> 
> },
> 
> {
> 
> "name": "kea-dhcp4.commands",
> 
> "output_options": [
> 
> {
> 
> "output": "syslog"
> 
> }
> 
> ],
> 
> "severity": "DEBUG",
> 
> "debuglevel": 99
> 
> },
> 
> {
> 
> "name": "kea-dhcp4.http",
> 
> "output_options": [
> 
> {
> 
> "output": "syslog"
> 
> }
> 
> ],
> 
> "severity": "DEBUG",
> 
> "debuglevel": 99
> 
> },
> 
> {
> 
> "name": "kea-dhcp4.callouts",
> 
> "output_options": [
> 
> {
> 
> "output": "syslog"
> 
> }
> 
> ],
> 
> "severity": "DEBUG",
> 
> "debuglevel": 99
> 
> }],
> 
> "authoritative": false,
> 
> "boot-file-name": "",
> 
> "calculate-tee-times": true,
> 
> "client-classes": [
> 
> {
> 
> "boot-file-name": "",
> 
> "name": "pxe",
> 
> "next-server": "10.0.0.12",
> 
> "only-if-required": true,
> 
> "option-data": [
> 
> {
> 
> "always-send": false,
> 
> "code": 66,
> 
> "csv-format": true,
> 
> "data": "10.0.0.12",
> 
> "name": "tftp-server-name",
> 
> "space": "dhcp4"
> 
> },
> 
> {
> 
> "always-send": false,
> 
> "code": 67,
> 
> "csv-format": true,
> 
> "data": "grldr",
> 
> "name": "boot-file-name",
> 
> "space": "dhcp4"
> 
> }
> 
> ],
> 
> "option-def": [ ],
> 
> "server-hostname": "",
> 
> "test": "member('ALL')"
> 
> },
> 
> {
> 
> "boot-file-name": "",
> 
> "name": "voip",
> 
> "next-server": "10.0.0.10",
> 
> "only-if-required": true,
> 
> "option-data": [
> 
> {
> 
> "always-send": false,
> 
> "code": 66,
> 
> "csv-format": true,
> 
> "data": "10.0.0.10",
> 
> "name": "tftp-server-name",
> 
> "space": "dhcp4"
> 
> },
> 
> {
> 
> "always-send": false,
> 
> "code": 67,
> 
> "csv-format": true,
> 
> "data": "grldr1",
> 
> "name": "boot-file-name",
> 
> "space": "dhcp4"
> 
> }
> 
> ],
> 
> "option-def": [ ],
> 
> "server-hostname": "",
> 
> "test": "member('ALL')"
> 
> }
> 
> ],
> 
> "control-socket": {
> 
> "socket-name": "/tmp/kea-dhcp4-ctrl.sock",
> 
> "socket-type": "unix"
> 
> },
> 
> "decline-probation-period": 86400,
> 
> "dhcp-ddns": {
> 
> "enable-updates": false,
> 
> "generated-prefix": "myhost",
> 
> "max-queue-size": 1024,
> 
> "ncr-format": "JSON",
> 
> "ncr-protocol": "UDP",
> 
> "override-client-update": false,
> 
> "override-no-update": false,
> 
> "qualifying-suffix": "",
> 
> "replace-client-name": "never",
> 
> "sender-ip": "0.0.0.0",
> 
> "sender-port": 0,
> 
> "server-ip": "127.0.0.1",
> 
> "server-port": 53001
> 
> },
> 
> "dhcp-queue-control": {
> 
> "capacity": 500,
> 
> "enable-queue": false,
> 
> "queue-type": "kea-ring4"
> 
> },
> 
> "dhcp4o6-port": 0,
> 
> "echo-client-id": true,
> 
> "expired-leases-processing": {
> 
> "flush-reclaimed-timer-wait-time": 5,
> 
> "hold-reclaimed-time": 1800,
> 
> "max-reclaim-leases": 100,
> 
> "max-reclaim-time": 250,
> 
> "reclaim-timer-wait-time": 10,
> 
> "unwarned-reclaim-cycles": 5
> 
> },
> 
> "hooks-libraries": [
> 
> {
> 
> "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_lease_cmds.so"
> 
> }
> 
> ],
> 
> "host-reservation-identifiers": [ "hw-address"],
> 
> "interfaces-config": {
> 
> "interfaces": [ "*" ],
> 
> "re-detect": true
> 
> },
> 
> "lease-database": {
> 
> "name": "/var/lib/kea/dhcp4.leases",
> 
> "persist": true,
> 
> "type": "memfile"
> 
> },
> 
> "match-client-id": false,
> 
> "next-server": "0.0.0.0",
> 
> "option-data": [
> 
> {
> 
> "always-send": false,
> 
> "code": 6,
> 
> "csv-format": true,
> 
> "data": "10.0.0.1",
> 
> "name": "domain-name-servers",
> 
> "space": "dhcp4"
> 
> },
> 
> {
> 
> "always-send": false,
> 
> "code": 15,
> 
> "csv-format": true,
> 
> "data": "lab.winitlab.com",
> 
> "name": "domain-name",
> 
> "space": "dhcp4"
> 
> },
> 
> {
> 
> "always-send": false,
> 
> "code": 119,
> 
> "csv-format": false,
> 
> "data": "057465636F6D046E6E6F76027275000A7465636F6D67726F757002727500",
> 
> "name": "domain-search",
> 
> "space": "dhcp4"
> 
> }
> 
> ],
> 
> "option-def": [ ],
> 
> "t1-percent": 0.5,
> 
> "t2-percent": 0.875,
> 
> "reservation-mode": "all",
> 
> "sanity-checks": {
> 
> "lease-checks": "warn"
> 
> },
> 
> "server-hostname": "",
> 
> "server-tag": "",
> 
> "shared-networks": [ ],
> 
> "subnet4": [
> 
> {
> 
> "4o6-interface": "",
> 
> "4o6-interface-id": "",
> 
> "4o6-subnet": "",
> 
> "authoritative": false,
> 
> "calculate-tee-times": true,
> 
> "id": 18,
> 
> "match-client-id": false,
> 
> "next-server": "1.1.1.1",
> 
> "option-data": [
> 
> {
> 
> "always-send": false,
> 
> "code": 3,
> 
> "csv-format": true,
> 
> "data": "10.0.50.1",
> 
> "name": "routers",
> 
> "space": "dhcp4"
> 
> },
> 
> {
> 
> "always-send": false,
> 
> "code": 6,
> 
> "csv-format": true,
> 
> "data": "10.200.0.1",
> 
> "name": "domain-name-servers",
> 
> "space": "dhcp4"
> 
> },
> 
> {
> 
> "always-send": false,
> 
> "code": 15,
> 
> "csv-format": true,
> 
> "data": "bncvbn.nnn",
> 
> "name": "domain-name",
> 
> "space": "dhcp4"
> 
> }
> 
> ],
> 
> "pools": [
> 
> {
> 
> "option-data": [ ],
> 
> "pool": "10.0.50.10-10.0.50.80"
> 
> }
> 
> ],
> 
> "relay": {
> 
> "ip-addresses": [ "10.0.50.1" ]
> 
> },
> 
> "reservation-mode": "all",
> 
> "reservations": [],
> 
> "subnet": "10.0.50.0/24",
> 
> "t1-percent": 0.5,
> 
> "t2-percent": 0.875,
> 
> "valid-lifetime": 86400
> 
> }
> 
> ],
> 
> "t1-percent": 0.5,
> 
> "t2-percent": 0.875,
> 
> "valid-lifetime": 4000
> 
> }
> 
> }
> 
> --
> 
> _______________________