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Unable to get Host information using IfIptoHost or ITopologyManager untill I do ping/pingall

asked 2014-09-05 10:47:59 -0700

Hi Folks,

I am working on OSGI module to forward traffic. I am implementing IListenDataPacket and in receiveDataPacket method I need host information(mac address, ip address, node connectors etc). Currently I am using IfIptoHost and ITopologyManager to get Host information. I am able to get this details only when I do ping / pingall. Otherwise it returns empty result set. Please advise.

Also noticed that, until we do ping/pingall the hosts are not seen on opendaylight console topology diagram. Is this a desired behavior?

Please advise.

Thanks, Darpan Mhatre

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answered 2014-09-06 17:05:05 -0700


The controller learns about the host using ARP, as the Switch will punt the ARP packet to the controller. So till an ARP packet is sent from the host then the controller won't know there is any host connect.

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Thank you Chris! So is there a way to get host information in few seconds using opendaylight API's OR some other work out. Right now I have 50 switches and 50 hosts and its taking forever to pingall. Thanks, Darpan Mhatre

Darpan Mhatre ( 2014-09-08 07:26:51 -0700 )edit

This isn't an issue with OpenDaylight or anything that OpenDaylight can fix. 1. Workaround would be if you're using a custom script in mininet is to run a loop for h1 ping h2, h3 .. h50 with ping count 1. 2. Just cancel the pingall after H1 has ping everything.

Chris O'Shea ( 2014-09-08 12:48:23 -0700 )edit

Thank you Chris, that reduced some time. I think this workaround will work for me for now. And sure was not saying that's the issue with opendaylight, but wanted to know if there is any way to do this or was i missing something. Thank you once again.

Darpan Mhatre ( 2014-09-09 06:45:57 -0700 )edit

I had the same issue. My approach is similar to what Chris suggested, except you only need to run ping between each pair, so only N/2 pings are needed. In addition, I set the ping timeout to 1 second in additional to ping count of 1. I am not sure if a shorter timeout may be specified.

Yiliang ( 2014-09-09 16:07:36 -0700 )edit

Thank you Yiliang! that will squeeze some more time for sure.

Darpan Mhatre ( 2014-09-10 07:18:42 -0700 )edit
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Asked: 2014-09-05 10:47:59 -0700

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Last updated: Sep 06 '14