[ovs-dev] [cfm_v2 5/9] cfm: Remove cfm_remote_mpid configuration.

[Ben Pfaff]

On Fri, Sep 09, 2011 at 12:58:36PM -0700, Ethan Jackson wrote:
> > Also, am I reading the code correctly that too many RMPs triggers an
> > unexpected_recv fault? ?Is that what we want?
> 
> This is an edge case I suppose.  I made a judgement call that it
> should but I'd like to here another opinion.  I'm basically worried
> about the case where someone is flooding CFM PDUs with randomly
> generated MPIDs.  It's not clear what the right response is in this
> case, but it seems like a fail-closed approach is appropriate.
> Especially if a controller is assuming that the cfm_remote_mpids
> column is complete, this gives an indication that there is a problem.

OK.

It's easy enough to change our decision later.

> > I think that there's more than one reason that a CFM can fault, but
> > the documentation only mentions one.
> 
> I've added the following paragraph to the cfm_fault column documentation:
> 
>           Faults can be triggered for several reasons.  Most importantly they
>           are triggered when no CCMs are received for a period of 3.5 times the
>           transmission interval. Faults are also triggered when any CCMs
>           indicate that a Remote Maintenance Point is not receiving CCMs but
>           able to send them.  Finally, a fault is triggered if a CCM is
>           received which indicates unexpected configuration.  Notably, this
>           case arises when a CCM is received which advertises the local MPID.

That is very complete.  Thank you.