Martin is of course correct that OpenFlow does not require flow expirations to be reliable. However, if you believe that Open vSwitch is dropping flow expirations, please let us know, because we have designed Open vSwitch never to drop flow expirations.
On Thu, Apr 29, 2010 at 02:46:24PM -0700, Martin Casado wrote: > It could very well be the case the the OpenFlow image you are using will > drop flow expirations. There is nothing in the spec which requires them to > be reliable and we regularly loose them in transit. Even if the counter is > 0, a flow expiration message should be sent to the controller (unless there > is a bug). > > >> Hi >> Sorry to bother others. I have a general question about flow-expire >> message. I want to know if there is any situation that a switch doesnt >> send flow-expire message even a flow expires, or, is there any chance the >> controller receives flow-expire message but drops it because it is out of >> buffer? Also I have questions about the first packet of a flow. >> My NOX controller fails to receive flow expire message from some flows of >> some switch. I havent checked the tcpdump files yet, because the traffic >> volume is not small. The module maintains every new flow and delete it >> once it expire. But it turns out that some flows continue being remained >> after there is no traffic. >> My NOX periodically queries flow size of all the flows maintained. I find >> out that all the left flows in the NOX have size 1, this shows that their >> sizes are not updated since they have arrived. >> *I want to know whether the first packet will update the counter in the >> first switch after this packet is sent back from controller? From document >> this packet is sent to the outport directly, but it turns out that it will >> still update the counter, at least I see this is the case for many flows. >> But, if the packet is received (from controller) by the first switch >> before the rule is established, what will happen? I guess in this case the >> counter is still 0. * >> *If a counter is 0, will the flow-expire message be sent back to the >> controller? * >> Any suggestions will be helpful. Thank you. >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> nox-dev mailing list >> [email protected] >> http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org >> > > > _______________________________________________ > nox-dev mailing list > [email protected] > http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org _______________________________________________ nox-dev mailing list [email protected] http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org
