Thanks Flavio for your hints!!
I am afraid Spanning tree solution could not be a solution to exploit
multipath topologies.
I've been looking for some solution in the line I commented (about caching
the appearance of broadcast ARP classifying them by [datapath id (switch),
src_ip, dst_ip]) and I have found an interesting thread in the mailing list
(http://sourceforge.net/p/ryu/mailman/message/33076908/). However, I am
still not able to make it run properly.
I think this solution is missing someone providing the routes, so my idea
was to mix this work with yours about shortest path forwarding (
http://sdn-lab.com/2014/12/25/shortest-path-forwarding-with-openflow-on-ryu/)
but I am afraid the topology discovery module has some problems as I
pointed out your blog. Maybe I avoid the ARP storm but now, there is the
LLDP storm.
Any hint about how to get the stable network topology without flooding the
controller?
Thank you very much all!
RyuJordiSDN
2015-01-20 15:40 GMT+01:00 Flavio Castro <[email protected]>:
> Spanning tree is the short (not complete) answer.
>
> The problem is that mac_learning uses the action flood for ARP packets.
>
> I'm not 100% sure on the solution.
>
> Flávio Castro Jr.
> MSCS student at Georgia Tech
> B.S.E in Networks Engineering from the University of Brasilia.
> CCNA Certified
> (404) 660-9373
>
> On Tue, Jan 20, 2015 at 3:59 AM, Jordi Baranda <[email protected]>
> wrote:
>
>> Dear all,
>>
>> I am new in this world of SDN and based upon some comments on the net and
>> I decided to start by using the Ryu/mininet/ovs friendly environment to
>> start with it. After reading the Ryubook I am trying to develop my own
>> application which tries to exploit the redundancy in a multipath topology
>> to perform load balancing in a round robin fashion.
>> Then, I create the topology the following topology in mininet (sorry for
>> the ASCII type draw)
>>
>> h3 --- s3 -------- s4 ------- h4
>> | |
>> | |
>> h1----s1-----------s2 ------- h2
>>
>> When I run the simple_switch Ryu app, I started to see a lot of packet-in
>> events. There was a storm of ARP broadcast packets which are overloading
>> the controller. Reading in the Ryubook I saw that the spanning tree
>> protocol handles this, but as far as I have understood this is not suitable
>> to exploit multipath topologies.
>>
>> Does anyone have an idea on how to avoid this storm of broadcast ARP
>> requests?
>> My first approach was to cache the appearance of broadcast ARP
>> classifying them by [datapath id (switch), src_ip, dst_ip] with the hope
>> that they were only broadcast once at each switch but I think I have not
>> been able to properly implement it.
>> I think the other problem is that I have to provide a route, isn't it? I
>> was thinking on using the NetworkX library for such purpose.
>>
>> Any hint will be welcome
>>
>> Thank you very much for your time and attention
>>
>> Jordi
>>
>>
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>>
>
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New Year. New Location. New Benefits. New Data Center in Ashburn, VA.
GigeNET is offering a free month of service with a new server in Ashburn.
Choose from 2 high performing configs, both with 100TB of bandwidth.
Higher redundancy.Lower latency.Increased capacity.Completely compliant.
http://p.sf.net/sfu/gigenet
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