1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
// 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": [
{
"id": 1,
"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 whether the server should look up global reservations.
"reservations-global": false,
// Specify whether the server should look up in-subnet reservations.
"reservations-in-subnet": true,
// Specify whether the 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"
}
]
}
}
|
