// This is an example configuration file for the DHCPv4 server in Kea.
// It demonstrates how global host reservations can be configured.
// The global reservations are not associated with any subnet. They
// are assigned regardless of the subnet to which the DHCP client belongs.
// Global reservations are assigned to the DHCP clients using the
// same host identifier types as subnet specific reservations. This file
// contains multiple examples of host reservations using different
// identifier types, e.g. MAC address, client identifier etc.
{ "Dhcp4":

{
// Kea is told to listen on eth0 interface only.
  "interfaces-config": {
    "interfaces": [ "eth0" ]
  },

// We need to specify the database used to store leases. As of June
// 2022, three database backends are supported: MySQL, PostgreSQL and
// the in-memory database, Memfile.  We'll use memfile because it doesn't
// require any prior set up.
  "lease-database": {
      "type": "memfile",
      "lfc-interval": 3600
  },

// Addresses will be assigned with a lifetime of 4000 seconds.
  "valid-lifetime": 4000,

// Renew and rebind timers are commented out. This implies that options
// 58 and 59 will not be sent to the client. In this case it is up to
// the client to pick the timer values according to RFC2131. Uncomment the
// timers to send these options to the client.
//  "renew-timer": 1000,
//  "rebind-timer": 2000,

// Kea supports reservations by several different types of identifiers:
// hw-address (hardware/MAC address of the client), duid (DUID inserted by the
// client), client-id (client identifier inserted by the client), circuit-id
// (circuit identifier inserted by the relay agent) and flex-id (flexible
// identifier available when flex_id hook library is loaded). When told to do
// so, Kea can check for all of those identifier types, but it takes a costly
// database lookup to do so. It is therefore useful from a performance
// perspective to use only the reservation types that are actually used in a
// given network.

// The example below is not optimal from a performance perspective, but it
// nicely showcases the host reservation capabilities. Please use the minimum
// set of identifier types used in your network.
  "host-reservation-identifiers": [ "circuit-id", "hw-address", "duid",
                                    "client-id", "flex-id" ],

// This directive tells Kea that reservations are global. Note that this
// can also be specified at shared network and/or subnet level.
// "reservation-mode": "global",
// It is replaced by the "reservations-global", "reservations-in-subnet", and
// "reservations-out-of-pool" parameters.

// Specify whether the server should look up global reservations.
  "reservations-global": true,

// Specify whether the server should look up in-subnet reservations.
  "reservations-in-subnet": false,

// Specify whether the server can assume that all reserved addresses
// are out-of-pool.
// Ignored when reservations-in-subnet is false.
// If specified, it is inherited by "shared-networks" and "subnet4" levels.
  "reservations-out-of-pool": false,

// Define several global host reservations.
  "reservations": [

// This is a reservation for a specific hardware/MAC address. It's a very
// simple reservation: just an address and nothing else.
// Note it is not recommended but still allowed to reverse addresses at
// the global scope: as it breaks the link between the reservation and
// the subnet it can lead to a client localized in another subnet than
// its address belongs to.
    {
        "hw-address": "1a:1b:1c:1d:1e:1f",
        "ip-address": "192.0.2.201"
    },

// This is a reservation for a specific client-id. It also shows
// the this client will get a reserved hostname. A hostname can be defined
// for any identifier type, not just client-id. Either a hostname or
// an address is required.
    {
        "client-id": "01:11:22:33:44:55:66",
        "hostname": "special-snowflake"
    },

// The third reservation is based on DUID. This reservation also
// defines special option values for this particular client. If
// the domain-name-servers option would have been defined on a global,
// subnet or class level, the host specific values take precedence for
// this particular DHCP client.
    {
        "duid": "01:02:03:04:05",
        "ip-address": "192.0.2.203",
        "option-data": [ {
            "name": "domain-name-servers",
            "data": "10.1.1.202,10.1.1.203"
        } ]
    },

// The fourth reservation is based on circuit-id. This is an option inserted
// by the relay agent that forwards the packet from client to the server.
// In this example the host is also assigned vendor specific options.
    {
        "circuit-id": "01:11:22:33:44:55:66",
        "ip-address": "192.0.2.204",
        "option-data": [
            {
                "name": "vivso-suboptions",
                "data": "4491"
            },
            {
                "name": "tftp-servers",
                "space": "vendor-4491",
                "data": "10.1.1.202,10.1.1.203"
            }
        ]
    },

// This reservation is for a client that needs specific DHCPv4 fields to be
// set. Three supported fields are next-server, server-hostname and
// boot-file-name
    {
        "client-id": "01:0a:0b:0c:0d:0e:0f",
        "ip-address": "192.0.2.205",
        "next-server": "192.0.2.1",
        "server-hostname": "hal9000",
        "boot-file-name": "/dev/null"
    },

// This reservation is using flexible identifier. Instead of relying
// on specific field, sysadmin can define an expression similar to what
// is used for client classification,
// e.g. substring(relay[0].option[17],0,6). Then, based on the value of
// that expression for incoming packet, the reservation is matched.
// Expression can be specified either as hex or plain text using single
// quotes.
// Note: flexible identifier requires flex_id hook library to be
// loaded to work.
    {
        "flex-id": "'s0mEVaLue'",
        "ip-address": "192.0.2.206"
    }
  ],

  // Define a subnet.
    "subnet4": [
        {
           "pools": [ { "pool":  "192.0.2.1 - 192.0.2.200" } ],
           "id": 1,
           "subnet": "192.0.2.0/24",
           "interface": "eth0"
        }
    ],

// The following configures logging. It assumes that messages with at
// least informational level (info, warn, error and fatal) should be
// logged to stdout.
    "loggers": [
        {
            "name": "kea-dhcp4",
            "output_options": [
                {
                    "output": "stdout"
                }
            ],
            "severity": "INFO"
        }
    ]
}

}
