On May 25, 2012, at 3:23 AM, Mabry Tyson wrote: > I happened to notice this potential bug. I don't know whether there is > something else that might avoid this. And, again, I saw this in Nox Classic. > Maybe Nox/Pox does things differently, or maybe they have the same issue: > > nox.cc tells the switch to delete all the rules on registration of a switch. > Shouldn't a barrier message be sent immediately after that? It would seem > that otherwise a rule added after this might wind up getting deleted.
Without having thought about this much, this doesn't seem like it could be an issue. Deleting flows and adding flows are both done with flow_mods. The problem you describe would only seem to be possible if flow_mods were reordered relative to other flow_mods. If flow_mods were reordered, it seems as if the only way you could ever get predictable behavior doing anything at all would be to always send a barrier after every flow_mod, which seems unreasonable. Thus, it seems to me that any switch where this is true is simply broken. No? -- Murphy (Incidentally, there's a tracker on github for bug reports -- https://github.com/noxrepo/nox-classic/issues)
