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// This is an example configuration file for DHCPv6 server in Kea
// that showcases how to do host reservations. It is
// assumed that one subnet (2001:db8:1::/64) is available directly
// over eth0 interface. A number of hosts have various combinations
// of addresses and prefixes reserved for them.
{ "Dhcp6":
{
// 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
},
// This is pretty basic stuff, it has nothing to do with reservations.
"preferred-lifetime": 3000,
"valid-lifetime": 4000,
"renew-timer": 1000,
"rebind-timer": 2000,
// Kea supports three types of identifiers in DHCPv6: hw-address (hardware/MAC
// address of the client), duid (DUID inserted by the client) and flex-id
// (flexible identifier available when flex_id hook library is loaded) When told
// to do so, Kea can check for each of these 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.
"host-reservation-identifiers": [ "duid", "hw-address", "flex-id" ],
// The following list defines subnets. Subnet, pools and interface definitions
// are the same as in the regular scenario, without host reservations.
// least subnet and pool entries.
"subnet6": [
{
"subnet": "2001:db8:1::/48",
// This directive tells Kea that reservations may be made both in-pool
// and out-of-pool. For improved performance, you may move all reservations
// out of the dynamic pool and change reservation-mode to "out-of-pool".
// Kea will then be able to skip querying for host reservations when
// assigning leases from dynamic pool.
// "reservation-mode": "all",
// It is replaced by the "reservations-global", "reservations-in-subnet"
// and "reservations-out-of-pool" parameters.
// Specify if server should lookup global reservations.
"reservations-global": false,
// Specify if server should lookup in-subnet reservations.
"reservations-in-subnet": true,
// Specify if 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
// "subnet6" levels.
"reservations-out-of-pool": false,
"pools": [ { "pool": "2001:db8:1::/120" } ],
"pd-pools": [
{
"prefix": "2001:db8:1:8000::",
"prefix-len": 56,
"delegated-len": 64
}
],
"interface": "eth0",
// Host reservations. Define several reservations, note that
// they are all within the range of the pool of the dynamically
// allocated address. The server will exclude the addresses from this
// pool and only assign them to the client which has a reservation for
// them.
"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"
} ],
"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: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:cafe::2" ]
}
]
}
],
// 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-dhcp6",
"output_options": [
{
"output": "stdout"
}
],
"debuglevel": 0,
"severity": "INFO"
}
]
}
}
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