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// 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": "/tmp/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": "@libdir@/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": "@libdir@/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. 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": "@localstatedir@/log/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
}
]
}
}
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