+
+ <group title="Controller Status">
+ <column name="is_connected">
+ <code>true</code> if currently connected to this controller,
+ <code>false</code> otherwise.
+ </column>
+
+ <column name="role">
+ <p>The level of authority this controller has on the associated
+ bridge. Possible values are:</p>
+ <dl>
+ <dt><code>other</code></dt>
+ <dd>Allows the controller access to all OpenFlow features.</dd>
+ </dl>
+ <dl>
+ <dt><code>master</code></dt>
+ <dd>Equivalent to <code>other</code>, except that there may be at
+ most one master controller at a time. When a controller configures
+ itself as <code>master</code>, any existing master is demoted to
+ the <code>slave</code>role.</dd>
+ </dl>
+ <dl>
+ <dt><code>slave</code></dt>
+ <dd>Allows the controller read-only access to OpenFlow features.
+ Attempts to modify the flow table will be rejected with an
+ error. Slave controllers do not receive OFPT_PACKET_IN or
+ OFPT_FLOW_REMOVED messages, but they do receive OFPT_PORT_STATUS
+ messages.</dd>
+ </dl>
+ </column>
+
+ <column name="status">
+ <p>Key-value pairs that report controller status.</p>
+ <dl>
+ <dt><code>last_error</code></dt>
+ <dd>A human-readable description of the last error on the connection
+ to the controller; i.e. <code>strerror(errno)</code>. This key
+ will exist only if an error has occurred.</dd>
+ </dl>
+ <dl>
+ <dt><code>state</code></dt>
+ <dd>The state of the connection to the controller. Possible values
+ are: <code>VOID</code>, <code>BACKOFF</code>,
+ <code>CONNECTING</code>, <code>ACTIVE</code>, and
+ <code>IDLE</code>.</dd>
+ </dl>
+ <dl>
+ <dt><code>time_in_state</code></dt>
+ <dd>Seconds since connecting to (if currently connected) or
+ disconnecting from (if currently disconnected) this
+ controller.</dd>
+ </dl>
+ </column>
+ </group>