doc: Consider null buffer_id in first example
If the switch does not buffer the packet (like when using mininet), the example does not work.
For such cases, include the packet contents in  OFPPacketOut
@@ -69,9 +69,14 @@ the ports.
ofp_parser = dp.ofproto_parser
actions = [ofp_parser.OFPActionOutput(ofp.OFPP_FLOOD)]
+
+ data = None
+ if msg.buffer_id == ofp.OFP_NO_BUFFER
+ data = msg.data
+
out = ofp_parser.OFPPacketOut(
datapath=dp, buffer_id=msg.buffer_id, in_port=msg.in_port,
- actions=actions)
+ actions=actions, data = data)
dp.send_msg(out)
