On May 27, 2015, at 2:29 PM, Adam Pavlidis <adampavli...@gmail.com> wrote:
>>> Are you using l2_learning and only l2_learning? >>> >>> I am using l2_learning, log.level with --DEBUG flag, and a custom module >>> that only handles Flow Removed events (only to print them) >>> >>> >>> >>> Are you sure? Try monitoring the OpenFlow connection to the controller >>> (this can be done with Wireshark, for example, or with a little >>> modification to POX). Do you see packet-ins with the ARPs in them? >>> >>> Sorry you are right, by using Wireshark with OF dissector i see the packet >>> In messages containing arp. >>> However, since the hosts don't exchange ARP Messages, but POX receives >>> Packet In messages were do these messages come from? >>> Also, >>> why the ARP request packets encapsulated in Packet In target a specific >>> MAC, as opposed to usual ARP request targeting every MAC? Is it a >>> "keep-alive" like mechanism for ARP Cache entries, or am i way off base? >> >> Are you sure they're not? You've inspected the right interfaces with >> Wireshark or whatever? I am guessing they are there. (And that Linux's ARP >> logic is not as straightforward as one might imagine.) > > Well i was certain initially, but now i have some doubts that i did not do > something wrong in tcpdump. Now that i used wireshark not only to dissect the > OF messages but to inspect the OF Bridge interfaces i was proved wrong > again... > I guess i got carried away by me expectation not to sent/receive messages for > a host with an already known MAC and perhaps i terminated the capture > prematurely. > Seems like this is a Linux ARP logic matter as you said. I will search > further on that direction. If you find a nice reference on the ARP logic used, let me know. I'm always telling people it's not as simple as they think, but never have anything good to point them at. :) (For the record, the only reason I know this is because I saw it so often due to working on POX!) > Sorry for bothering you with this, and thanks again for all your help -- Murphy
