I heard this from my supervisor. I also think this is not resolved, because it seems hard to resolve this. I think to guarantee flow_mod be set up for every switch, it is better to install in the initial order, that means, the first switch installed first, because the packet will hit in this order. I think this is unresolved, because I occasionally saw this happens. I guess the only thing we can do is to handle new flow_in event.
On Mon, Feb 8, 2010 at 7:10 PM, kk yap <[email protected]> wrote: > Hi Guanyao, > > From what I know this is not resolved. Do you recall where you heard > that this is resolved in NOX 0.5? > > I put in a component in NOX 0.6 (not available publicly) to install > the route/tree in reverse order, i.e., destination first. This is not > foolproof either, since there is no guarantees on the flow_mod will > reach the switch in that order. Just does better than the current > order of installation. > > There exists a solution that totally removes the problem, but it adds > an RTT delay. Basically you can (in theory) do a barrier function for > each flow_mod and wait for all the replies before putting the flow_mod > to the source switch. > > Regards > KK > > On 8 February 2010 14:33, Guanyao Huang <[email protected]> wrote: >> Hi >> Sorry to bother others. >> In order to establish packet forwarding between switches, the rule >> should be sent to switch before the first packet is sent back. The >> race condition is the packet is sent back and even forwarded by the >> first switch, but it doesnt find a rule in the second switch although >> openflow command is already sent. I was told that conditions like this >> were resolved after nox 0.5. My version is 0.5.0-full-beta, but I >> still find this happens occasionally. Is there any other requirement >> on the version? Also, how did you gaurrantee these conditions are >> resolved. Did you try to control the delay of the packets on wire? >> Thanks. >> >> _______________________________________________ >> 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
