Murphy, I don't think that "link down" event is an issue even if there are some. If "h1 ping -c1 h3" doesn't work correctly, it doesn't work correctly all the time and this can be changed only during next run. And if we suggest that it doesn't follow the shortest path because link s21-s24 is down then "h1 ping-c1 h4" would act the same way (instead, it follows the shortest path that goes through the link s21-s24).
Yes, I'm using spanning_tree module. Sometimes, I see some extra ICMP messages. Maybe here "link down" events have something to do with it :) because next pings(during the same run) give normal results. I will try to use your version of POX. Thank you very much Tatyana ________________________________ From: Murphy McCauley [[email protected]] Sent: Sunday, August 26, 2012 10:04 PM To: Tatyana Yatskevich Cc: [email protected] Subject: Re: [nox-dev] issues with routing module On Aug 26, 2012, at 6:51 PM, Tatyana Yatskevich wrote: I don't see any down events and I never had a completely correct run. I attached a snapshot of passing control messages during the ping (destination MAC address was already discovered). We can see that the controller installs flow entries to first 4 switches and then to the rest 3. There are some "Poisoning message" from authenticator module which I don't understand. I actually don't remember if the down events will get printed on the console by default; it may make sense to write a small component that just prints link and switch down messages. My reason for asking is that I have long suspected that there may be an issue where you don't get optimal paths after links go down, but have never looked into it really deeply (and at this point, I probably never will). I tried POX controller and it looks like it works correctly so far. But I see a million of LLDP messages dropped.They don't seem to effect the network's working but they are disturbing cause they make a passing messages analysis more difficult. Are you also running the spanning_tree component? If not, you probably should. :) You also might get somewhat better results with the version in the github.com/MurphyMc/pox<http://github.com/MurphyMc/pox> fork, which is where my pre-upstream work is being collected. -- Murphy
