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Diffstat (limited to 'doc/sphinx/arm/dhcp4-srv.rst')
| -rw-r--r-- | doc/sphinx/arm/dhcp4-srv.rst | 232 |
1 files changed, 136 insertions, 96 deletions
diff --git a/doc/sphinx/arm/dhcp4-srv.rst b/doc/sphinx/arm/dhcp4-srv.rst index a45524e805..ba03f0a973 100644 --- a/doc/sphinx/arm/dhcp4-srv.rst +++ b/doc/sphinx/arm/dhcp4-srv.rst @@ -5932,55 +5932,67 @@ If the subnet does not belong to a shared network, the subnet is not changed once selected. If the subnet does not belong to a shared network, it is possible to -use host reservation-based client classification to select an address pool +use host reservation-based client classification to select a pool within the subnet as follows: -:: +.. code-block:: json - "Dhcp4": { - "client-classes": [ - { - "name": "reserved_class" - }, - { - "name": "unreserved_class", - "test": "not member('reserved_class')" - } - ], - "subnet4": [ - { - "id": 1, - "subnet": "192.0.2.0/24", - "reservations": [ - { - "hw-address": "aa:bb:cc:dd:ee:fe", - "client-classes": [ "reserved_class" ] - } - ], - "pools": [ - { - "pool": "192.0.2.10-192.0.2.20", - "client-classes": [ "reserved_class" ] - }, - { - "pool": "192.0.2.30-192.0.2.40", - "client-classes": [ "unreserved_class" ] - } - ] - } - ] + { + "Dhcp4": { + "client-classes": [ + { + "name": "reserved_class" + }, + { + "name": "unreserved_class", + "test": "not member('reserved_class')" + } + ], + "subnet4": [ + { + "id": 1, + "subnet": "192.0.2.0/24", + "reservations": [ + { + "hw-address": "aa:bb:cc:dd:ee:fe", + "client-classes": [ "unreserved_class" ] + } + ], + "pools": [ + { + "pool": "192.0.2.10 - 192.0.2.20", + "client-classes": [ "reserved_class" ] + }, + { + "pool": "192.0.2.30 - 192.0.2.40", + "client-classes": [ "reserved_class" ] + }, + { + "pool": "192.0.2.50 - 192.0.2.60" + } + ] + } + ] + } } -The ``reserved_class`` is declared without the ``test`` parameter because -it may only be assigned to the client via the host reservation mechanism. The +``reserved_class`` is declared without the ``test`` parameter because +it may only be assigned to a client via the host reservation mechanism. The second class, ``unreserved_class``, is assigned to clients which do not -belong to the ``reserved_class``. The first pool within the subnet is only -used for clients having a reservation for the ``reserved_class``. The -second pool is used for clients not having such a reservation. The -configuration snippet includes one host reservation which causes the client -with the MAC address aa:bb:cc:dd:ee:fe to be assigned to the -``reserved_class``. Thus, this client will be given an IP address from the -first address pool. +belong to the ``reserved_class``. + +The first pool with the subnet is used for clients not having such a reservation. +The second pool is only used for clients having a reservation for ``reserved_class``. +The third pool is an unrestricted pool for any clients, comprising of both +``reserved_class`` clients and ``unreserved_class``. + +The configuration snippet includes one host reservation which causes the client +with the MAC address ``aa:bb:cc:dd:ee:fe`` to be assigned to ``reserved_class``. +Thus, this client will be given an IP address from the second address pool. + +Reservations defined on a subnet that belongs to a shared network are not +visible to an otherwise matching client, so they cannot be used to select pools, +nor subnets for that matter. .. _subnet-selection-with-class-reservations4: @@ -5993,76 +6005,104 @@ client belongs to a shared network. In such a case it is possible to use classification to select a subnet within this shared network. Consider the following example: -:: +.. code-block:: json - "Dhcp4": { - "client-classes": [ - { - "name": "reserved_class" - }, - { - "name": "unreserved_class", - "test": "not member('reserved_class')" - } - ], - "reservations": [ - { - "hw-address": "aa:bb:cc:dd:ee:fe", - "client-classes": [ "reserved_class" ] - } - ], - # It is replaced by the "reservations-global", - # "reservations-in-subnet", and "reservations-out-of-pool" parameters. - # Specify if the server should look up global reservations. - "reservations-global": true, - # Specify if the server should look up in-subnet reservations. - "reservations-in-subnet": false, - # Specify if the server can assume that all reserved addresses - # are out-of-pool. It can be ignored because "reservations-in-subnet" - # is false, but if specified, it is inherited by "shared-networks" - # and "subnet4" levels. - # "reservations-out-of-pool": false, - "shared-networks": [ - { - "subnet4": [ + { + "Dhcp4": { + "client-classes": [ { - "id": 1, - "subnet": "192.0.2.0/24", - "pools": [ - { - "pool": "192.0.2.10-192.0.2.20", - "client-classes": [ "reserved_class" ] - } - ] + "name": "reserved_class" }, { - "id": 2, - "subnet": "192.0.3.0/24", - "pools": [ + "name": "unreserved_class", + "test": "not member('reserved_class')" + } + ], + "reservations": [ + { + "hw-address": "aa:bb:cc:dd:ee:fe", + "client-classes": [ "reserved_class" ] + } + ], + "reservations-global": true, + "reservations-in-subnet": false, + "shared-networks": [ + { + "name": "net", + "subnet4": [ { - "pool": "192.0.3.10-192.0.3.20", - "client-classes": [ "unreserved_class" ] + "id": 1, + "subnet": "192.0.2.0/24", + "pools": [ + { + "pool": "192.0.2.10-192.0.2.20", + "client-classes": [ "unreserved_class" ] + }, + { + "pool": "192.0.2.30-192.0.2.40", + "client-classes": [ "unreserved_class" ] + } + ] + }, + { + "id": 2, + "subnet": "192.0.3.0/24", + "pools": [ + { + "pool": "192.0.3.10-192.0.3.20", + "client-classes": [ "reserved_class" ] + }, + { + "pool": "192.0.3.30-192.0.3.40", + "client-classes": [ "reserved_class" ] + } + ] + }, + { + "id": 3, + "subnet": "192.0.4.0/24", + "pools": [ + { + "pool": "192.0.4.10-192.0.4.20" + }, + { + "pool": "192.0.4.30-192.0.4.40" + } + ] } ] } ] - } - ] + } } This is similar to the example described in :ref:`pool-selection-with-class-reservations4`. This time, however, there -are two subnets, each of which has a pool associated with a different -class. The clients that do not have a reservation for the ``reserved_class`` -are assigned an address from the subnet 192.0.3.0/24. Clients with -a reservation for the ``reserved_class`` are assigned an address from -the subnet 192.0.2.0/24. The subnets must belong to the same shared network. +are three subnets, of which the first two have a pool associated with a different +class each. + +The clients that do not have a reservation for ``reserved_class`` +are assigned an address from the first subnet and when that is filled from +the third subnet. Clients with a reservation for ``reserved_class`` are assigned +an address from the second subnet and when that is filled from the third subnet. + +The subnets must belong to the same shared network. + +For a subnet to be restricted to a certain class, or skipped, all of the pools +inside that subnet must be guarded by ``reserved_class`` or ``unreserved_class`` +respectively. + In addition, the reservation for the client class must be specified at the global scope (global reservation) and ``reservations-global`` must be set to ``true``. -In the example above, the ``client-classes`` could also be specified at the -subnet level rather than the pool level, and would yield the same effect. +In the example above, the ``client-classes`` configuration parameter could also +be specified at the subnet level rather than the pool level, and would yield the +same effect. + +If the subnets were defined outside shared networks, and ``client-classes`` were +specified at the subnet level, then ``early-global-reservations-lookup`` would +also need to be enabled in order for subnet selection to work. .. _multiple-reservations-same-ip4: |