[pox-dev] questions about l2_learning vs l2_pairs

[Kostas Chartsias]

Hi all and thanks for the continuous support Murphy!!!
I am trying to understand the differences between l2_learning and l2_pairs switch cause i am writing a report for a project.
1)The l2_learning switch drops lldp packets and l2_pairs doesn't.Is there any side effect by not dropping lldp packets?2)The l2_learning switch handles multicast traffic and l2_pairs doesn't .I guess it's an extra feature and nothing else.3)The more confusing feature in l2_learning is why drop packets if the output port is the same as input.How is it possible and why it hasnt been implemented in the l2_pairs.

Moreover i would like to describe in details their functionality.We have  pc1 and pc2 with arp cache empty and i ping pc1->pc2
*l2_learning switchPc1 arp broadcast.Switch sends packet to controller.Controller sends packet out flood and add to its decitionary mac and port of the incoming packet.Pc2 responds with its mac and controller adds to its dictionary mac and port of pc2.Installs one flow for the arp responce.After that the echo request and reply go to the controller and it installs new flows for each of them,cause l2_learning works with full match.*l2_pairsPc1 arp broadcast.Switch sends packet to controller.Controller sends packet out flood and adds to its decitionary mac and port of the incoming packet.Pc2 responds with its mac and controller adds to its dictionary mac and port of pc2.Installs one flow for the arp responce.(Same thing as the previous one).But now after that with echo request it adds one more flow and that's the end of this,cause it works only in the data linke layer and doesnt care for the protocols above it.

To sum up.for two hosts
l2_learning 1flow for arp reply,1flow for echo request and 1flow for echo reply and more flows for different ports etc...even though they are the same hosts
l2_pairs 1 flow for arp reply,1 flow for echo request or whatever we send and that's the end of it(i assume we dont have timeouts and flows are permanent)

Any help or any correction would be very much appreciated!!!thanks in advance!

 
  
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.noxrepo.org/pipermail/pox-dev-noxrepo.org/attachments/20150527/21a1cbf5/attachment.html>