Kea DHCP
Control
Get DHCP4 Server Status
keactrl status -s dhcp4
Reload DHCP4 Server
You'll want to do this after making changes to the kea-dhcp4.conf file.
keactrl reload -s dhcp4
Leases
Leases are stored in memfile, by default. But you can also have them written to a CSV file:
"lease-database": {
"type": "memfile", // write leases to memfile...
"persist": true,
"name": "/tmp/kea-leases4.csv", // ...but also write them to csv
"lfc-interval": 3600,
"max-row-errors": 100
},
MySQL
To use host reservations from MySQL, you need to add the "hosts-database" section to the "Dhcp4" section of the config file, like this:
"hosts-database": {
"type": "mysql",
"name": "kea_db",
"user": "kea-user",
"password": "super-secret-password",
"host": "localhost",
"port": 3306
},
Subnet-Ids need to be defined in your subnet declarations, too.
You can use both the hosts database and the configuration file for host reservations at the same time.
IPv4 Reservations
Insert Statement Example:
SELECT host_id,dhcp_identifier,dhcp4_subnet_id,ipv4_address,hostname FROM hosts;
START TRANSACTION;
SET @ipv4_reservation='10.1.70.11';
SET @hostname = 'windows-pc';
SET @identifier_type='hw-address';
SET @identifier_value='be:ef:be:ef:be:ef';
SET @dhcp4_subnet_id=70;
INSERT INTO hosts (dhcp_identifier,
dhcp_identifier_type,
dhcp4_subnet_id,
ipv4_address,
hostname)
VALUES (UNHEX(REPLACE(@identifier_value, ':', )),
(SELECT type FROM host_identifier_type WHERE name=@identifier_type),
@dhcp4_subnet_id,
INET_ATON(@ipv4_reservation),
@hostname);
COMMIT;
Sync db Between Two Hosts
Manual Dump of Host Reservations
mysqldump kea_db -u kea-user -p --tables hosts > kea-hosts.sql
Crontab for use on Standby peers
*/5 * * * * mysqldump -h net1.lambnet.us -u net2 -p<password> --single-transaction kea_db hosts | mysql -u net2 -p<password> kea_db
...
MySQL Performance Tuning
Configure in /etc/mysql/my.cnf:
[mysqld] innodb_flush_log_at_trx_commit=2
SystemD Tip
You may encounter an issue where kea-dhcp4 fails to start at boot. Try adding this to /usr/lib/systemd/system/kea-dhcp4.service, at the end of the [Unit] section:
After=mysqld.service
Kea-Shell
Commands
[ { "arguments": [ "build-report", "config-backend-pull", "config-get", "config-reload", "config-set", "config-test", "config-write", "dhcp-disable", "dhcp-enable", "ha-continue", "ha-heartbeat", "ha-maintenance-cancel", "ha-maintenance-notify", "ha-maintenance-start", "ha-reset", "ha-scopes", "ha-sync", "ha-sync-complete-notify", "lease4-add", "lease4-del", "lease4-get", "lease4-get-all", "lease4-get-by-client-id", "lease4-get-by-hostname", "lease4-get-by-hw-address", "lease4-get-page", "lease4-resend-ddns", "lease4-update", "lease4-wipe", "lease6-add", "lease6-bulk-apply", "lease6-del", "lease6-get", "lease6-get-all", "lease6-get-by-duid", "lease6-get-by-hostname", "lease6-get-page", "lease6-resend-ddns", "lease6-update", "lease6-wipe", "leases-reclaim", "libreload", "list-commands", "server-tag-get", "shutdown", "statistic-get", "statistic-get-all", "statistic-remove", "statistic-remove-all", "statistic-reset", "statistic-reset-all", "statistic-sample-age-set", "statistic-sample-age-set-all", "statistic-sample-count-set", "statistic-sample-count-set-all", "status-get", "version-get" ], "result": 0 } ]
Get Status
kea-shell --host 10.144.30.8 --service dhcp4 status-get