kea/doc/examples/kea4/leases-expiration.json

// This is an example configuration file for the DHCPv4 server in Kea.
// It provides parameters controlling processing of expired leases,
// a.k.a. leases reclamation.

{ "Dhcp4":

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

// We need to specify the the database used to store leases. As of
// September 2016, four database backends are supported: MySQL,
// PostgreSQL, Cassandra, 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
  },

// The following parameters control processing expired leases. Expired
// leases will be reclaimed periodically according to the
// "reclaim-timer-wait-time" parameter. Reclaimed leases will be held in
// the database for 1800s to facilitate lease affinity. After this
// period the leases will be removed.  The frequency of removal is
// controlled by the "flush-reclaimed-timer-wait-time" parameter. The
// lease reclamation routine will process at most 500 leases or will
// last for at most 100ms, during a single run. If there are still some
// unreclaimed leases after 10 attempts, a warning message is issued.
  "expired-leases-processing": {
    "reclaim-timer-wait-time": 5,
    "hold-reclaimed-time": 1800,
    "flush-reclaimed-timer-wait-time": 10,
    "max-reclaim-leases": 500,
    "max-reclaim-time": 100,
    "unwarned-reclaim-cycles": 10
  },

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

// The following list defines subnets. We have only one subnet
// here. We tell Kea that it is directly available over local interface.
  "subnet4": [
    {
       "pools": [ { "pool":  "192.0.2.1 - 192.0.2.200" } ],
       "subnet": "192.0.2.0/24",
       "interface": "ethX"
    }
  ]
},

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

}