kea/doc/examples/kea4/classify.json

// This is an example configuration file for the DHCPv4 server in Kea.
// The purpose of this example is to showcase how clients can be classified.

{ "Dhcp4": {

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

// Let's use the simplest backend: memfile and use some reasonable values
// for timers. They are of no concern for the classification demonstration.
  "lease-database": { "type": "memfile" },
  "renew-timer": 1000,
  "rebind-timer": 2000,
  "valid-lifetime": 4000,

// This list defines several classes that incoming packets can be assigned to.
// One packet can belong to zero or more classes.
  "client-classes": [

// The first class attempts to match the whole hardware address to a specific
// value. All incoming packets with that MAC address will get a special
// value of the option. If there are many hosts that require special
// treatment, it is much better to use host reservations. However, doing
// tricks with MAC addresses may prove useful in some cases, e.g.
// by matching OUI to known values we can detect certain vendors.
  {
      "name": "special_snowflake",
      "test": "pkt4.mac == 0x010203040506",
      "option-data": [{
          "name": "domain-name-servers",
          "data": "127.0.0.1"
      }]
  },

// Let's classify all incoming DISCOVER (message type 1) to a separate
// class.
  {
      "name": "discovers",
      "test": "pkt4.msgtype == 1"
  },

// Clients are supposed to set the transaction-id field to a random value.
// Clients that send it with 0 are most likely broken. Let's mark them
// as such.
  {
      "name": "broken",
      "test": "pkt4.transid == 0"
  },

// Let's pick VoIP phones. Those that send their class identifiers
// as Aastra, should belong to VoIP class. For a list of all options,
// see www.iana.org/assignments/bootp-dhcp-parameters/.
// In this particular class, we want to set specific values
// of certain DHCPv4 fields. If the incoming packet matches the
// test, those fields will be set in outgoing responses.
// The option 43 is defined to encapsulate suboption in the aastra space.
  {
      "name": "VoIP",
      "test": "substring(option[60].hex,0,6) == 'Aastra'",
      "next-server": "192.0.2.254",
      "server-hostname": "hal9000",
      "boot-file-name": "/dev/null",
      "option-def": [ {
          "name": "vendor-encapsulated-options",
          "code": 43,
          "type": "empty",
          "encapsulate": "aastra" } ]
  }

  ],

// The following list defines subnets. For some subnets we defined
// a class that is allowed in that subnet. If not specified,
// everyone is allowed. When a class is specified, only packets belonging
// to that class are allowed for that subnet.
  "subnet4": [
    {
// This one is for VoIP devices only.
        "pools": [ { "pool":  "192.0.2.1 - 192.0.2.200" } ],
        "subnet": "192.0.2.0/24",
        "client-class": "VoIP",
        "interface": "ethX"
    },
// This one doesn't have any client-class specified, so everyone
// is allowed in. The normal subnet selection rules still apply,
// though. There is also a static class reservation for a client
// using MAC address 1a:1b:1c:1d:1e:1f. This client will always
// be assigned to this class.
    {
        "pools": [ { "pool":  "192.0.3.1 - 192.0.3.200" } ],
        "subnet": "192.0.3.0/24",
        "reservations": [
        {
            "hw-address": "1a:1b:1c:1d:1e:1f",
            "client-classes": [ "VoIP" ]
        } ],
        "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"
        }
    ]
}

}