[ovs-discuss] Interval /transmission timer for particular MPs in CFM

edward wilson edward.wilson2601 at gmail.com
Sun Mar 18 15:33:02 UTC 2012


Hi,

After installing and configuring OVS, br0 will be there.
1. is that mean I have to use its physical interface with which br0
attached like eth0.
2. is that mean I have to use 2 physical OVS machines at least for cfm
set-up.
3. configuration of cfm_remote_mpid ,I got from ovs-vsctl config book. so
my command would be now:-
ovs-vsctl set Interface br0 cfm_mpid=1
then how a machine will identify its remote MPs.

-Ed



On Sat, Mar 17, 2012 at 2:30 AM, Ben Pfaff <blp at nicira.com> wrote:

> cfm_remote_mpids (note the "s") is not a column that you as a user
> write.  It is a column that ovs-vswitchd writes.
>
> Ordinarily one would configure CFM on a physical interface or a
> tunnel.  br0 is an internal interface.
>
> On Fri, Mar 16, 2012 at 09:19:44AM +0530, edward wilson wrote:
> > OVS version 1.2.2
> >
> > following commands run on machine-
> >
> > first mahine-
> > ovs-vsctl set Interface br0 cfm_mpid=1 cfm_remote_mpid=2
> >
> > second machine--
> >  ovs-vsctl set Interface br0 cfm_mpid=2 cfm_remote_mpid=1
>  >
> > -Ed
> >
> >
> >
> > On Fri, Mar 16, 2012 at 8:53 AM, edward wilson
> > <edward.wilson2601 at gmail.com>wrote:
> >
> > >
> > >
> > > First machine-
> > >
> > > ovs-appctl cfm/show br0
> > >
> > > MPID 1: fault recv_fault
> > >
> > >                  Interval: 1000ms
> > >
> > >                 Next CCM tx: 403ms
> > >
> > >                 Next fault check: 2744ms
> > >
> > >
> > >
> > > Remote MPID 2: fault
> > >
> > >                 Recv since check: false
> > >
> > >
> > >
> > > Second machime-
> > >
> > > ovs-appctl cfm/show br0
> > >
> > > MPID 2: fault recv_fault
> > >
> > >                  Interval: 1000ms
> > >
> > >                 Next CCM tx: 403ms
> > >
> > >                 Next fault check: 2744ms
> > >
> > >
> > >
> > > Remote MPID 1: fault
> > >
> > >                 Recv since check: false
> > >
> > > -Ed
> > >
> > >  On Thu, Mar 15, 2012 at 10:12 PM, Ben Pfaff <blp at nicira.com> wrote:
> > >
> > >> Maybe you should show us your configuration.  It seems likely that
> > >> there is just some misunderstanding.
> > >>
> > >> On Thu, Mar 15, 2012 at 05:30:19PM +0530, edward wilson wrote:
> > >> > when I am creating cfm between two ovs ( one physical and other VM
> on
> > >> same
> > >> > machine) , CCM packet are with RDI bit set.
> > >> > connection is not making between MPs.
> > >> > both are on same bradcast domain.
> > >> >
> > >> > tried with two physical machines with OVS by giving same vlan id,
> but
> > >> > result is same.
> > >> >
> > >> > -ed
> > >> >
> > >> > On Sat, Feb 18, 2012 at 2:27 AM, Ethan Jackson <ethan at nicira.com>
> > >> wrote:
> > >> >
> > >> > >   > Ed- same broadcast domain , you mean- I have to assign all
> MPs in
> > >> one
> > >> > > vlan
> > >> > > > or same network should be provided.
> > >> > >
> > >> > > The CFM module sends multicast CCMs on the interface upon which
> it's
> > >> > > configured.  Presumably, multicast/broadcasts packets egressing
> this
> > >> > > interface can reach some set of other hosts on the network.  This
> set
> > >> > > can be restricted by using VLANs or other strategies.  How this is
> > >> > > done precisely, is out of the scope of the CFM module.  The
> important
> > >> > > thing is, when the CFM module broadcasts CCMs, all other MPs that
> > >> > > these CCMs reach need to have the same transmission interval.
> > >> > >
> > >> > > >> > 2) along with that I want to know how can I see the current
> timer
> > >> > > value
> > >> > > >> > by
> > >> > > >> > any show command for particular MPids, I didn' tfind any
> command
> > >> for
> > >> > > >> > this.
> > >> > > >>
> > >> > > >> ovs-appctl cfm/show will give you information about currently
> > >> configured
> > >> > > >> CFM.
> > >> > >
> > >> > > The CFM module doesn't maintain a separate timer for each remote
> MP.
> > >> > > Instead it maintains one timer that triggers at an interval of 3.5
> > >> > > times the transmission interval.  When the CFM module receives a
> CCM
> > >> > > from a remote MP, it sets a flag for this remote MP indicating the
> > >> > > reception.   When the timer triggers, any MPs which are not
> flagged
> > >> > > are considered unreachable and removed.  All of this information
> (the
> > >> > > timers, the set of reachable MPs, the reception flag) is available
> > >> > > from the ovs-appctl cfm/show command.
> > >> > >
> > >> > > It's also worth noting that we don't implement the full 802.1ag
> > >> > > specification.  We implement a much simplified version which
> maintains
> > >> > > the packet format, but is quite a bit less sophisticated than the
> > >> > > standard.
> > >> > >
> > >> > > Ethan
> > >> > >
> > >> > >
> > >> > >
> > >> > > >
> > >> > > >
> > >> > > > Ed- this command shows the configured CFM,my doubt was when CCM
> > >> received
> > >> > > > then timer gets restarted then how can I check /verfiy this that
> > >> timer
> > >> > > has
> > >> > > > been restarted for a MP or MPs
> > >> > > >>
> > >> > > >>
> > >> > > >> Ethan
> > >> > > >>
> > >> > > >>
> > >> > > >>
> > >> > > >> >
> > >> > > >> > Regards,
> > >> > > >> > Ed
> > >> > > >> >
> > >> > > >> > _______________________________________________
> > >> > > >> > discuss mailing list
> > >> > > >> > discuss at openvswitch.org
> > >> > > >> > http://openvswitch.org/mailman/listinfo/discuss
> > >> > > >> >
> > >> > > >
> > >> > > >
> > >> > >
> > >>
> > >> > _______________________________________________
> > >> > discuss mailing list
> > >> > discuss at openvswitch.org
> > >> > http://openvswitch.org/mailman/listinfo/discuss
> > >>
> > >>
> > >
>
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