[ovs-discuss] Quick acting bypass?

[Ben Pfaff]

The "bundle" and "bundle_load" actions allow for this, as do "select"
groups, bonds, and probably other constructs I've forgotten about too.

On Fri, Jun 03, 2016 at 05:02:38PM -0400, Lax Clarke wrote:
> Is there a way to write OVS rules to act on BFD state (i.e., modify tables
> based on BFD state) ?
> 
> On Thu, Jun 2, 2016 at 2:38 AM, Ben Pfaff <blp at ovn.org> wrote:
> 
> > On Thu, Jun 02, 2016 at 12:41:32AM -0400, Lax Clarke wrote:
> > > Suppose we have two OVS switches A and B attached to two NICs
> > respectively.
> > > I have a VM in between that normally bridges traffic between A and B (and
> > > thus bridges traffic ingressing on the NICs).
> > >
> > > Is there a way to set up a bypass mechanism, whereby switches A or B can
> > > quickly determine that the VM is no longer bridging traffic, then cause a
> > > bypass around the VM?
> > >
> > > Maybe some sort of heartbeats sent between the bridges that can detect
> > > missing heartbeats on sub-10 seconds time frames?
> >
> > This sounds like a use for CFM or BFD.  OVS supports both, see
> > ovs-vswitchd.conf.db(5).
> >