Lastly upgrading from isc-dhcp-server to isc-kea for my homelab

Damaged down that approach, the migration did not look terribly scary—and it is made simpler by the truth that the Kea default config information come stuffed with descriptive feedback and configuration examples to crib from. (And, once more, ISC has performed an excellent job with the docs for Kea. All variations, from deprecated to bleeding-edge, have thorough and in depth on-line documentation in the event you’re interested by what a given possibility does or the place to use it—and, as famous above, there are additionally the equipped pattern config information to tear aside if you would like extra detailed examples.)

Configuration time for DHCP

We have now two Kea functions to configure, so we’ll do DHCP first after which get to the DDNS aspect. (Although the DHCP config file additionally incorporates a bunch of DDNS stuff, so I assume if we’re being pedantic, we’re setting each up directly.)

The primary file to edit, in the event you put in Kea by way of bundle supervisor, is /and so forth/kea/kea-dhcp4.conf. The file ought to have already got some fairly sane defaults in it, and it is value taking a second to look via the feedback and see what these defaults are and what they imply.

Here is a evenly sanitized model of my working kea-dhcp4.conf file:

{
  "Dhcp4": {
    "control-socket": {
      "socket-type": "unix",
      "socket-name": "/tmp/kea4-ctrl-socket"
    },
    "interfaces-config": {
      "interfaces": ["eth0"],
      "dhcp-socket-type": "uncooked"
    },
    "dhcp-ddns": {
      "enable-updates": true
    },
    "ddns-conflict-resolution-mode": "no-check-with-dhcid",
    "ddns-override-client-update": true,
    "ddns-override-no-update": true,
    "ddns-qualifying-suffix": "bigdinosaur.lan",
    "authoritative": true,
    "valid-lifetime": 86400,
    "renew-timer": 43200,
    "expired-leases-processing": {
      "reclaim-timer-wait-time": 3600,
      "hold-reclaimed-time": 3600,
      "max-reclaim-leases": 0,
      "max-reclaim-time": 0
    },
    "loggers": [
    {
      "name": "kea-dhcp4",
      "output_options": [
        {
          "output": "syslog",
          "pattern": "%-5p %mn",
          "maxsize": 1048576,
          "maxver": 8
        }
      ],
      "severity": "INFO",
      "debuglevel": 0
      }
    ],
    "reservations-global": false,
    "reservations-in-subnet": true,
    "reservations-out-of-pool": true,
    "host-reservation-identifiers": [
      "hw-address"
    ],
    "subnet4": [
      {
        "id": 1,
        "subnet": "10.10.10.0/24",
        "pools": [
          {
            "pool": "10.10.10.170 - 10.10.10.254"
          }
        ],
        "option-data": [
          {
            "name": "subnet-mask",
            "data": "255.255.255.0"
          },
          {
            "name": "routers",
            "data": "10.10.10.1"
          },
          {
            "name": "broadcast-address",
            "data": "10.10.10.255"
          },
          {
            "name": "domain-name-servers",
            "data": "10.10.10.53"
          },
          {
            "name": "domain-name",
            "data": "bigdinosaur.lan"
          }
        ],
        "reservations": [
          {
            "hostname": "host1.bigdinosaur.lan",
            "hw-address": "aa:bb:cc:dd:ee:ff",
            "ip-address": "10.10.10.100"
          },
          {
            "hostname": "host2.bigdinosaur.lan",
            "hw-address": "ff:ee:dd:cc:bb:aa",
            "ip-address": "10.10.10.101"
          }
        ]
      }
    ]
  }
}

The primary stanzas arrange the management socket on which the DHCP course of listens for administration API instructions (we’re not going to arrange the administration device, which is overkill for a homelab, however it will make sure the socket exists in the event you ever resolve to go in that path). Additionally they arrange the interface on which Kea listens for DHCP requests, they usually inform Kea to pay attention for these requests in uncooked socket mode. You nearly definitely need uncooked as your DHCP socket sort (see right here for why), however this may also be set to udp if wanted.