<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">On May 27, 2015, at 2:29 PM, Adam Pavlidis <<a href="mailto:adampavlidis@gmail.com">adampavlidis@gmail.com</a>> wrote:<br><div><br class="Apple-interchange-newline"><blockquote type="cite">
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<div>Are you using l2_learning and only
l2_learning?</div>
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I am using l2_learning, log.level with --DEBUG
flag, and a custom module that only handles Flow
Removed events (only to print them)<br>
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<div>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?</div>
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Sorry you are right, by using Wireshark with OF
dissector i see the packet In messages containing
arp. <br>
However, since the hosts don't exchange ARP
Messages, but POX receives Packet In messages were
do these messages come from? <br>
Also,<br>
why the ARP request packets encapsulated in Packet
In target a specific<br>
MAC, as opposed to usual ARP request targeting
every MAC? Is it a <br>
"keep-alive" like mechanism for ARP Cache entries,
or am i way off base?<br>
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<div>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.)</div>
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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...<br>
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.<br>
Seems like this is a Linux ARP logic matter as you said. I will
search further on that direction.<br></div></blockquote><div><br></div><div>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!)</div><br><blockquote type="cite"><div bgcolor="#FFFFFF" text="#000000">
Sorry for bothering you with this, and thanks again for all your
help<br>
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</blockquote></div><br><div>-- Murphy</div></body></html>