Device Configuration
====================
Each switch in Trellis requires a device config.

.. code-block:: json

    {
      "devices" : {
        "of:0000000000000001" : {
          "segmentrouting" : {
            "ipv4NodeSid" : 101,
            "ipv4Loopback" : "192.168.0.201",
            "ipv6NodeSid" : 111,
            "ipv6Loopback" : "2000::c0a8:0201",
            "routerMac" : "00:00:00:00:02:01",
            "isEdgeRouter" : true,
            "adjacencySids" : []
          },
          "basic" : {
            "name" : "Leaf-R1",
            "driver" : "ovs-ofdpa"
          }
        }
      }
    }

- ``of:0000000000000001``: DPID of the device.

- ``ipv4NodeSid``: IPv4 node segment ID, which is used as an MPLS label in
  forwarding IPv4 traffic. Can be arbitrary and should be globally unique.

- ``ipv4Loopback``: IPv4 loopback address. Can be arbitrary, should be globally
  unique and should not be part of the same subnet(s) defined on the data plane
  ports (see port config).

- ``ipv6NodeSid``: IPv6 node segment ID, which is used as an MPLS label in
  forwarding IPv6 traffic. Can be arbitrary and should be globally unique. Only
  required when using IPv6.

- ``ipv6Loopback``: IPv6 loopback address. Can be arbitrary, should be globally
  unique and should not be part of the same subnet(s) defined on the data plane
  ports (see port config).  Only required when using IPv6.

- ``routerMac``: Router MAC address. Can be arbitrary and should be globally
  unique.  This MAC address will be used to reply the ARP request for the
  loopback IP or the Interface IP that will be introduced later.  (We recommend
  using the MAC address of the device's management interface as the router
  MAC.)

- ``isEdgeRouter``: True for leaf switches. False for spine switches.

- ``adjacencySids``: Deprecated.  Just put an empty array for now.

- ``name``: Name of the device. It is an arbitrary name to identify the device easily.

- ``driver``: This tells ONOS which OpenFlow driver should be loaded for this
  device. It overrides the driver selected by ONOS automatically when the
  device connects.

    - When using OpenvSwitch, set this to ``ovs-ofdpa``

    - When using hardware switches, set this to ``ofdpa3`` or eliminate
      ``driver`` entirely as the correct driver configuration will be set
      automatically by ONOS

.. caution::
    We should avoid using reserved MPLS labels for ``ipv4NodeSid`` and
    ``ipv6NodeSid``.  Please check here for the reserved values:
    http://www.iana.org/assignments/mpls-label-values/mpls-label-values.xhtml

.. note::
    Most of the Trellis configurations support dynamic configuration updates.
    Unfortunately, Trellis currently **do not support dynamic device
    configuration updates**.  You will have to restart the device when if
    corresponding device configuration changes.

    Having said that, when introducing a completely new device in the network,
    the device configurations pushed before the device's connection should
    apply correctly.