// This is a basic configuration for the Kea DHCPv6 server. Subnet declarations
// are mostly commented out and no interfaces are listed. Therefore, the servers
// will not listen or respond to any queries.
// The basic configuration must be extended to specify interfaces on which
// the servers should listen. There are a number of example options defined.
// These probably don't make any sense in your network. Make sure you at least
// update the following, before running this example in your network:
// - change the network interface names
// - change the subnets to match your actual network
// - change the option values to match your network
//
// This is just a very basic configuration. Kea comes with large suite (over 30)
// of configuration examples and extensive Kea User's Guide. Please refer to
// those materials to get better understanding of what this software is able to
// do. Comments in this configuration file sometimes refer to sections for more
// details. These are section numbers in Kea User's Guide. The version matching
// your software should come with your Kea package, but it is also available
// in ISC's Knowledgebase (https://kea.readthedocs.io; the direct link for
// the stable version is https://kea.readthedocs.io/).
//
// This configuration file contains only DHCPv6 server's configuration.
// If configurations for other Kea services are also included in this file they
// are ignored by the DHCPv6 server.
{

// DHCPv6 configuration starts here. This section will be read by DHCPv6 server
// and will be ignored by other components.
"Dhcp6": {
    // Add names of your network interfaces to listen on.
    "interfaces-config": {
        // You typically want to put specific interface names here, e.g. eth0
        // but you can also specify unicast addresses (e.g. eth0/2001:db8::1) if
        // you want your server to handle unicast traffic in addition to
        // multicast. (DHCPv6 is a multicast based protocol).
        "interfaces": [ ]
    },

    // Kea supports control channel, which is a way to receive management commands
    // while the server is running. This is a Unix domain socket that receives
    // commands formatted in JSON, e.g. config-set (which sets new configuration),
    // config-reload (which tells Kea to reload its configuration from file),
    // statistic-get (to retrieve statistics) and many more. For detailed
    // description, see Sections 9.12, 16 and 15.
    "control-socket": {
        "socket-type": "unix",
        "socket-name": "kea6-ctrl-socket"
    },

    // Use Memfile lease database backend to store leases in a CSV file.
    // Depending on how Kea was compiled, it may also support SQL databases
    // (MySQL and/or PostgreSQL). Those database backends require more
    // parameters, like name, host and possibly user and password.
    // There are dedicated examples for each backend. See Section 8.2.2 "Lease
    // Storage" for details.
    "lease-database": {
        // Memfile is the simplest and easiest backend to use. It's an in-memory
        // C++ database that stores its state in CSV file.
        "type": "memfile",
        "lfc-interval": 3600
    },

    // Kea allows storing host reservations in a database. If your network is
    // small or you have few reservations, it's probably easier to keep them
    // in the configuration file. If your network is large, it's usually better
    // to use database for it. To enable it, uncomment the following:
    // "hosts-database": {
    //     "type": "mysql",
    //     "name": "kea",
    //     "user": "kea",
    //     "password": "kea",
    //     "host": "localhost",
    //     "port": 3306
    // },
    // See Section 8.2.3 "Hosts storage" for details.

    // Setup reclamation of the expired leases and leases affinity.
    // Expired leases will be reclaimed every 10 seconds. Every 25
    // seconds reclaimed leases, which have expired more than 3600
    // seconds ago, will be removed. The limits for leases reclamation
    // are 100 leases or 250 ms for a single cycle. A warning message
    // will be logged if there are still expired leases in the
    // database after 5 consecutive reclamation cycles.
    // If both "flush-reclaimed-timer-wait-time" and "hold-reclaimed-time" are
    // not 0, when the client sends a release message the lease is expired
    // instead of being deleted from the lease storage.
    "expired-leases-processing": {
        "reclaim-timer-wait-time": 10,
        "flush-reclaimed-timer-wait-time": 25,
        "hold-reclaimed-time": 3600,
        "max-reclaim-leases": 100,
        "max-reclaim-time": 250,
        "unwarned-reclaim-cycles": 5
    },

    // These parameters govern global timers. Addresses will be assigned with
    // preferred and valid lifetimes being 3000 and 4000, respectively. Client
    // is told to start renewing after 1000 seconds. If the server does not
    // respond after 2000 seconds since the lease was granted, a client is
    // supposed to start REBIND procedure (emergency renewal that allows
    // switching to a different server).
    "renew-timer": 1000,
    "rebind-timer": 2000,
    "preferred-lifetime": 3000,
    "valid-lifetime": 4000,

    // These are global options. They are going to be sent when a client requests
    // them, unless overwritten with values in more specific scopes. The scope
    // hierarchy is:
    // - global
    // - subnet
    // - class
    // - host
    //
    // Not all of those options make sense. Please configure only those that
    // are actually useful in your network.
    //
    // For a complete list of options currently supported by Kea, see
    // Section 8.2.9 "Standard DHCPv6 Options". Kea also supports
    // vendor options (see Section 7.2.10) and allows users to define their
    // own custom options (see Section 7.2.9).
    "option-data": [
        // When specifying options, you typically need to specify
        // one of (name or code) and data. The full option specification
        // covers name, code, space, csv-format and data.
        // space defaults to "dhcp6" which is usually correct, unless you
        // use encapsulate options. csv-format defaults to "true", so
        // this is also correct, unless you want to specify the whole
        // option value as long hex string. For example, to specify
        // domain-name-servers you could do this:
        // {
        //     "name": "dns-servers",
        //     "code": 23,
        //     "csv-format": "true",
        //     "space": "dhcp6",
        //     "data": "2001:db8:2::45, 2001:db8:2::100"
        // }
        // but it's a lot of writing, so it's easier to do this instead:
        {
            "name": "dns-servers",
            "data": "2001:db8:2::45, 2001:db8:2::100"
        },

        // Typically people prefer to refer to options by their names, so they
        // don't need to remember the code names. However, some people like
        // to use numerical values. For example, DHCPv6 can optionally use
        // server unicast communication, if extra option is present. Option
        // "unicast" uses option code 12, so you can reference to it either
        // by "name": "unicast" or "code": 12. If you enable this option,
        // you really should also tell the server to listen on that address
        // (see interfaces-config/interfaces list above).
        {
            "code": 12,
            "data": "2001:db8::1"
        },

        // String options that have a comma in their values need to have
        // it escaped (i.e. each comma is preceded by two backslashes).
        // That's because commas are reserved for separating fields in
        // compound options. At the same time, we need to be conformant
        // with JSON spec, that does not allow "\,". Therefore the
        // slightly uncommon double backslashes notation is needed.

        // Legal JSON escapes are \ followed by "\/bfnrt character
        // or \u followed by 4 hexadecimal numbers (currently Kea
        // supports only \u0000 to \u00ff code points).
        // CSV processing translates '\\' into '\' and '\,' into ','
        // only so for instance '\x' is translated into '\x'. But
        // as it works on a JSON string value each of these '\'
        // characters must be doubled on JSON input.
        {
            "name": "new-posix-timezone",
            "data": "EST5EDT4\\,M3.2.0/02:00\\,M11.1.0/02:00"
        },

        // Options that take integer values can either be specified in
        // dec or hex format. Hex format could be either plain (e.g. abcd)
        // or prefixed with 0x (e.g. 0xabcd).
        {
            "name": "preference",
            "data": "0xf0"
        },

        // A few options are encoded in (length, string) tuples
        // which can be defined using only strings as the CSV
        // processing computes lengths.
        {
            "name": "bootfile-param",
            "data": "root=/dev/sda2, quiet, splash"
        }
    ],

    // Another thing possible here are hooks. Kea supports a powerful mechanism
    // that allows loading external libraries that can extract information and
    // even influence how the server processes packets. Those libraries include
    // additional forensic logging capabilities, ability to reserve hosts in
    // more flexible ways, and even add extra commands. For a list of available
    // hook libraries, see https://gitlab.isc.org/isc-projects/kea/wikis/Hooks-available.
    // "hooks-libraries": [
    //   {
    //       // Forensic Logging library generates forensic type of audit trail
    //       // of all devices serviced by Kea, including their identifiers
    //       // (like MAC address), their location in the network, times
    //       // when they were active etc.
    //       "library": "/usr/local/lib/kea/hooks/libdhcp_legal_log.so",
    //       "parameters": {
    //           "path": "/var/lib/kea",
    //           "base-name": "kea-forensic6"
    //       }
    //   },
    //   {
    //       // Flexible identifier (flex-id). Kea software provides a way to
    //       // handle host reservations that include addresses, prefixes,
    //       // options, client classes and other features. The reservation can
    //       // be based on hardware address, DUID, circuit-id or client-id in
    //       // DHCPv4 and using hardware address or DUID in DHCPv6. However,
    //       // there are sometimes scenario where the reservation is more
    //       // complex, e.g. uses other options that mentioned above, uses part
    //       // of specific options or perhaps even a combination of several
    //       // options and fields to uniquely identify a client. Those scenarios
    //       // are addressed by the Flexible Identifiers hook application.
    //       "library": "/usr/local/lib/kea/hooks/libdhcp_flex_id.so",
    //       "parameters": {
    //           "identifier-expression": "relay6[0].option[37].hex"
    //       }
    //   }
    // ],

    // Below an example of a simple IPv6 subnet declaration. Uncomment to enable
    // it. This is a list, denoted with [ ], of structures, each denoted with
    // { }. Each structure describes a single subnet and may have several
    // parameters. One of those parameters is "pools" that is also a list of
    // structures.
    "subnet6": [
        {
            // This defines the whole subnet. Kea will use this information to
            // determine where the clients are connected. This is the whole
            // subnet in your network.

            // Subnet identifier should be unique for each subnet.
            "id": 1,

            // This is mandatory parameter for each subnet.
            "subnet": "2001:db8:1::/64",

            // Pools define the actual part of your subnet that is governed
            // by Kea. Technically this is optional parameter, but it's
            // almost always needed for DHCP to do its job. If you omit it,
            // clients won't be able to get addresses, unless there are
            // host reservations defined for them.
            "pools": [ { "pool": "2001:db8:1::/80" } ],

            // Kea supports prefix delegation (PD). This mechanism delegates
            // whole prefixes, instead of single addresses. You need to specify
            // a prefix and then size of the delegated prefixes that it will
            // be split into. This example below tells Kea to use
            // 2001:db8:1::/56 prefix as pool and split it into /64 prefixes.
            // This will give you 256 (2^(64-56)) prefixes.
            "pd-pools": [
                {
                    "prefix": "2001:db8:8::",
                    "prefix-len": 56,
                    "delegated-len": 64

                    // Kea also supports excluded prefixes. This advanced option
                    // is explained in Section 9.2.9. Please make sure your
                    // excluded prefix matches the pool it is defined in.
                    // "excluded-prefix": "2001:db8:8:0:80::",
                    // "excluded-prefix-len": 72
                }
            ],
            "option-data": [
                // You can specify additional options here that are subnet
                // specific. Also, you can override global options here.
                {
                    "name": "dns-servers",
                    "data": "2001:db8:2::dead:beef, 2001:db8:2::cafe:babe"
                }
            ],

            // Host reservations can be defined for each subnet.
            //
            // Note that reservations are subnet-specific in Kea. This is
            // different than ISC DHCP. Keep that in mind when migrating
            // your configurations.
            "reservations": [
                // This is a simple host reservation. The host with DUID matching
                // the specified value will get an address of 2001:db8:1::100.
                {
                    "duid": "01:02:03:04:05:0A:0B:0C:0D:0E",
                    "ip-addresses": [ "2001:db8:1::100" ]
                },

                // This is similar to the previous one, but this time the
                // reservation is done based on hardware/MAC address. The server
                // will do its best to extract the hardware/MAC address from
                // received packets (see 'mac-sources' directive for
                // details). This particular reservation also specifies two
                // extra options to be available for this client. If there are
                // options with the same code specified in a global, subnet or
                // class scope, the values defined at host level take
                // precedence.
                {
                    "hw-address": "00:01:02:03:04:05",
                    "ip-addresses": [ "2001:db8:1::101" ],
                    "option-data": [
                        {
                            "name": "dns-servers",
                            "data": "3000:1::234"
                        },
                        {
                            "name": "nis-servers",
                            "data": "3000:1::234"
                        }],

                    // This client will be automatically added to certain
                    // classes.
                    "client-classes": [ "special_snowflake", "office" ]
                },

                // This is a bit more advanced reservation. The client with the
                // specified DUID will get a reserved address, a reserved prefix
                // and a hostname.  This reservation is for an address that it
                // not within the dynamic pool.  Finally, this reservation
                // features vendor specific options for CableLabs, which happen
                // to use enterprise-id 4491. Those particular values will be
                // returned only to the client that has a DUID matching this
                // reservation.
                {
                    "duid": "01:02:03:04:05:06:07:08:09:0A",
                    "ip-addresses": [ "2001:db8:1:0:cafe::1" ],
                    "prefixes": [ "2001:db8:2:abcd::/64" ],
                    "hostname": "foo.example.com",
                    "option-data": [
                        {
                            "name": "vendor-opts",
                            "data": "4491"
                        },
                        {
                            "name": "tftp-servers",
                            "space": "vendor-4491",
                            "data": "3000:1::234"
                        }
                    ]
                },

                // 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": "'somevalue'",
                    "ip-addresses": [ "2001:db8:1:0:cafe::2" ]
                }
            ]
        }
        // More subnets can be defined here.
        //      {
        //          "subnet": "2001:db8:2::/64",
        //          "pools": [ { "pool": "2001:db8:2::/80" } ]
        //      },
        //      {
        //          "subnet": "2001:db8:3::/64",
        //          "pools": [ { "pool": "2001:db8:3::/80" } ]
        //      },
        //      {
        //          "subnet": "2001:db8:4::/64",
        //          "pools": [ { "pool": "2001:db8:4::/80" } ]
        //      }
    ],

    // Client-classes can be defined here. See "client-classes" in Dhcp4 for
    // an example.

    // DDNS information (how the DHCPv6 component can reach a DDNS daemon)

    // Logging configuration starts here. Kea uses different loggers to log various
    // activities. For details (e.g. names of loggers), see Chapter 18.
    "loggers": [
    {
        // This specifies the logging for kea-dhcp6 logger, i.e. all logs
        // generated by Kea DHCPv6 server.
        "name": "kea-dhcp6",
        "output_options": [
            {
                // Specifies the output file. There are several special values
                // supported:
                // - stdout (prints on standard output)
                // - stderr (prints on standard error)
                // - syslog (logs to syslog)
                // - syslog:name (logs to syslog using specified name)
                // Any other value is considered a name of the file
                "output": "kea-dhcp6.log"

                // Shorter log pattern suitable for use with systemd,
                // avoids redundant information
                // "pattern": "%-5p %m\n",

                // This governs whether the log output is flushed to disk after
                // every write.
                // "flush": false,

                // This specifies the maximum size of the file before it is
                // rotated.
                // "maxsize": 1048576,

                // This specifies the maximum number of rotated files to keep.
                // "maxver": 8
            }
        ],
        // This specifies the severity of log messages to keep. Supported values
        // are: FATAL, ERROR, WARN, INFO, DEBUG
        "severity": "INFO",

        // If DEBUG level is specified, this value is used. 0 is least verbose,
        // 99 is most verbose. Be cautious, Kea can generate lots and lots
        // of logs if told to do so.
        "debuglevel": 0
    }
  ]
}
}
