[ovs-dev] [PATCH] bond: Only drop packets that indicate moves on SLB bonds.

[Ben Pfaff]

Yes, that makes sense to me.  I thought that we had essentially agreed
on that change earlier in fact.

On Fri, Nov 04, 2011 at 12:00:26PM -0700, Ethan Jackson wrote:
> This looks good to me.
> 
> Unrelated to this patch:
> 
> The more I think about it.  I don't think falling back to balance-slb
> is the appropriate thing to do when lacp negotiations fail for
> balance-tcp bonds.  I think it will be much safer to fall back to
> active-backup.
> 
> Generally speaking, in a properly configured system, LACP negotiations
> won't fail.  Therefore LACP negotiation failures represent exceptional
> circumstances in which safety seems like it would extremely valuable.
> I'm worried about the case where someone configures their network with
> a LACP bond going to 2 or more separate switches (completely valid
> according to the spec).  If something goes wrong, they will fall back
> to balance-slb and thus be running an slb bond in a distributed manner
> across multiple switches.  This should "theoretically" work, but feels
> risky to me.  I'm confident active-backup will work in all cases
> however.
> 
> Thoughts?
> Ethan
> 
> On Fri, Nov 4, 2011 at 09:51, Ben Pfaff <blp at nicira.com> wrote:
> > On Fri, Oct 28, 2011 at 01:28:57PM -0700, Ben Pfaff wrote:
> >> SLB bonds, for important reasons, drop most incoming packets that indicate
> >> that a MAC has moved to the bond from another port. ?These reasons do not
> >> apply to other types of bonds, but until now OVS has still dropped them.
> >>
> >> This fixes the problem. ?It changes behavior of active-backup bonds and
> >> stable bonds, neither of which has the same problem as SLB. ?Behavior of
> >> SLB bonds and TCP bonds in SLB fallback mode is unaffected.
> >>
> >> Bug #7928.
> >
> > This needs review. ?It shouldn't be very hard.
> >