topic replying ARP message in Software Defined Networking

replying ARP message

low2215 — Mon, 24 Feb 2014 07:05:12 GMT

I have intercept a ARP request packet from a director packet handler.

I wish to create an ARP reply message.

I have created a packetout message and fill in the ARP reply packet data.

I can see the OFP+ARP packet out message in wireshark with ARP reply message embedded .

But there is no ARP reply packet .

I have done the following :

OfmMutablePacketOut packetout = (OfmMutablePacketOut)MessageFactory.create(version, MessageType.PACKET_OUT);

    ActOutput act = (ActOutput)ActionFactory.createAction(version,
                               ActionType.OUTPUT,context.getPacketIn().getInPort(),ActOutput.CONTROLLER_NO_BUFFER);
    packetout.inPort(context.getPacketIn().getInPort());
    packetout.addAction(act);
    packetout.bufferId(BufferId.NO_BUFFER);
    packetout.data(<arp reply data byte>);

controllerService.send(packetout.toImmutable(), context.srcEvent().dpid()); // where context is the MessageContext

Anyone has any tips how i should solve this ?

Thanks

Re: replying ARP message

low2215 — Thu, 27 Feb 2014 06:42:09 GMT

I have change the ActOutput Port to Port.IN_PORT, this seems to solve the problem .

ActOutput act = (ActOutput)ActionFactory.createAction(version,
ActionType.OUTPUT,Port.IN_PORT,ActOutput.CONTROLLER_NO_BUFFER);
packetout.inPort(context.getPacketIn().getInPort());

Re: replying ARP message

sdnindia — Mon, 03 Mar 2014 18:56:31 GMT

Hi,

Please let us know if your problem is solved.

Please feel free to reply incase you have more questions around the same topic or open a new thread if new topic.

If you feel your question has been answered, please do let us know by marking this response as an accepted solution.

Thanks
HP SDN Team

Re: replying ARP message

ShaunWackerly — Sat, 08 Mar 2014 00:41:29 GMT

Just so you're clear on why this difference made things work:

- context.getPacketIn().getInPort() will be the ingress port for THIS packet

- Port.IN_PORT will be the ingress port for whatever packet MATCHED the rule which uses the ActOutput object

Chances are that the first ARP reply worked (because THIS packet is the MATCHED packet), and subsequent ARP replies didn't work because they came in on different ingress ports and matched the same rule.