[pox-dev] How to use sendToDPID(dpid,packet) function?

[Murphy McCauley]

I think sendToDPID() just doesn't do what you think it does.  It is for sending OpenFlow commands to a switch -- the same as connection.send(), except it looks up the connection for you based on DPID.  I believe you're trying to use it to send a packet out of some port on a switch.  There's an obvious piece of information missing here -- sendToDPID takes a DPID, but how would it know which port you want to send the packet out of?

What you need to do is create an ofp_packet_out() which has an output action to the appropriate port and the data you want to send as the 'data' attribute. This is similar to the flood() function in l2_learning which is in your source.  There are even closer examples in other modules (e.g., misc.dhcpd).  Then send *that* using sendToDPID(), or in your case -- just use connection.send().

-- Murphy 

On Jul 5, 2013, at 12:52 PM, Kavit Shah wrote:

> Command line with log, my code and screen shot of the wireshrak are attached in the text and png files.
> 
> I am using HP Pro curve switch, i think it supports OF 1.0 spec.
> 
>  
> #####################################
> #####################################
> 
> Important part of my code in the attached file
> 
> #####################################
> #####################################
> 
> Questions:
> 
> 1) sendToDPID function is not working the way I expect it to work. According to me if that function works I should see packet out in wireshark.
> 
> 2) Am I extracting dpid of the switch correctly ?
> 
> 3) What is the reason for getting an error while switch connects to the POX controller ?
> 
> ERROR:openflow.of_01:[00-16-b9-ce-2f-40|800 1] OpenFlow Error:
> [00-16-b9-ce-2f-40|800 1] Error: header:
> [00-16-b9-ce-2f-40|800 1] Error:   version: 1
> [00-16-b9-ce-2f-40|800 1] Error:   type:    1 (OFPT_ERROR)
> [00-16-b9-ce-2f-40|800 1] Error:   length:  20
> [00-16-b9-ce-2f-40|800 1] Error:   xid:     7
> [00-16-b9-ce-2f-40|800 1] Error: type: OFPET_BAD_REQUEST (1)
> [00-16-b9-ce-2f-40|800 1] Error: code: OFPBRC_BAD_TYPE (1)
> [00-16-b9-ce-2f-40|800 1] Error: datalen: 8
> [00-16-b9-ce-2f-40|800 1] Error: 0000: 01 12 00 08 00 00 00 07                            ........
> 
> 
> <sendToDPID_question.txt><sendToDPID_wireshark.png>_______________________________________________
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