<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Hello …<div><br></div><div><table cellspacing="0" cellpadding="0" border="0" style="position: static; z-index: auto;"><tbody><tr><td valign="top"><p dir="ltr">I am working on a controller which calculate shrtest path from a function i have made and returns an array of switches in between source and destination switches... When a packet is received i calculate their source and dpids and calculate their shotest path. for example: for switch 1 and switch 7 there is a shortest path [2,3,4,7]<br>Now i want to install flows for them </p></td></tr></tbody></table><div><br></div></div><div>Currently I am doing this… It is sending the packet and installing flows but I cant ping … I am new to POX so if you can explain it in bit easier way !! Thanks</div><div><br></div><div><br></div><div><div>def _handle_PacketIn (self, event):</div><div><br></div><div> def flood(): #floods the packet</div><div> </div><div> msg = of.ofp_packet_out() </div><div> msg.actions.append(of.ofp_action_output(port = of.OFPP_FLOOD))</div><div> msg.data = packet_in.data </div><div> msg.in_port = in_port</div><div> self.connection.send(msg)</div><div><br></div><div> </div><div> def drop():# drops the message</div><div> </div><div> if packet_in.buffer_id is not None: </div><div><br></div><div> msg = of.ofp_packet_out()</div><div> msg.buffer_id = packet_in.buffer_id</div><div> </div><div> msg.in_port = in_port </div><div> self.connection.send(msg)</div><div><br></div><div><br></div><div> </div><div> packet = event.parsed </div><div> packet_in = event.ofp </div><div> in_port = event.port</div><div> #print in_port</div><div> dpid = event.dpid</div><div> </div><div> </div><div> </div><div> if packet.type == packet.LLDP_TYPE:</div><div> self.receive_topology_packet(dpid,in_port,packet)</div><div><br></div><div> return</div><div> </div><div> </div><div> </div><div> self.host_table[packet.src] = in_port</div><div> </div><div><br></div><div> if <a href="http://packet.dst.is">packet.dst.is</a>_multicast:</div><div> flood()</div><div> return</div><div> </div><div> if packet.dst not in self.host_table: # check for unknown destination</div><div> </div><div> flood()</div><div> return</div><div> </div><div> else:</div><div> </div><div> print "%s" %(packet.src)</div><div> print "%s" %(packet.dst)</div><div> p_s = str(packet.src)</div><div> p_d = str(packet.dst)</div><div> </div><div> dpid_src = dpid</div><div> print "src dpid",dpid_src</div><div> for s in range(len(switch)):</div><div><br></div><div> </div><div> if p_d[-1:] == str(switch[s]):</div><div> dpid_dst = switch[s]</div><div> print "dest dpid",dpid_dst</div><div><br></div><div> best_route = []</div><div> best_route = spf.shortest_path(dpid_src,dpid_dst)</div><div> best_route.reverse()</div><div> print best_route</div><div> </div><div> print " known"</div><div> </div><div><br></div><div> msg = of.ofp_flow_mod()</div><div><br></div><div> if not packet.type == packet.VLAN_TYPE:</div><div> print "attaching a vlan id"</div><div> msg.actions.append(of.ofp_action_vlan_vid(vlan_vid = dpid_dst))</div><div><br></div><div> elif dpid_src == dpid_dst:</div><div> print "arived at destination striping vtag"</div><div> msg.actions.append(of.ofp_action_strip_vlan()) </div><div><br></div><div> </div><div> if best_route:</div><div> if not best_route[0] == dpid_dst:</div><div> next_hop = best_route[0]</div><div> </div><div><br></div><div> if not dpid_src== dpid_dst:</div><div> for p in topo[dpid_src]:</div><div> temp = topo[dpid_src][p]</div><div> if temp [0]== next_hop: # in topo[dpid_src][p]:</div><div> print"yes"</div><div> print"p",p</div><div> #dp,op = topo[dpid][p]</div><div> op = p</div><div> print "outport",op</div><div> else:</div><div> print"we r at destination"</div><div> op = self.host_table[packet.dst]</div><div> print "op"</div><div><br></div><div> </div><div> print"sending flow" </div><div> msg = of.ofp_flow_mod() # installing flow</div><div> msg.match = of.ofp_match.from_packet(packet, in_port)</div><div> msg.idle_timeout = 10</div><div> msg.hard_timeout = 30</div><div> </div><div> msg.actions.append(of.ofp_action_output(port = op))</div><div> msg.data = packet_in</div><div> </div><div> self.connection.send(msg)</div><div> </div><div> msg = of.ofp_packet_out() </div><div> msg.actions.append(of.ofp_action_output(port = op))</div><div> msg.data = packet_in.data </div><div> msg.in_port = in_port</div><div> self.connection.send(msg)</div><div> print "flow sent"</div></div></body></html>