[ovs-dev] [PATCH v2] ovn: Update TODO, ovn-northd flow table design, ovn-architecture for L3.

Han Zhou zhouhan at gmail.com
Thu Oct 8 06:55:50 UTC 2015

Hi Ben,

Very nice document, and I have some questions.

On Tue, Oct 6, 2015 at 2:46 PM, Ben Pfaff <blp at nicira.com> wrote:
> This is a proposed plan for logical L3 in OVN.  It is not entirely
> complete but it includes many important details and I believe that it moves
> planning forward.
> Signed-off-by: Ben Pfaff <blp at nicira.com>
> ---
> v1->v2: Resolve comments from Justin and Russell posted to ovs-dev.

> +** OVN_SB schema
> +
Could you also describe something about the distributed and
non-distributed part of the logical router ports? How would them be
binded in ovn-sb schema?
A related question is, would it be possible to support completely
distributed logical router even for north-south traffic? I.e. no
special nodes are required for L3 GW, but every HV can perform like a

> +
> +** IP to MAC binding
> +
> +Somehow it has to be possible for an L3 logical router to map from an
> +IP address to an Ethernet address.  This can happen statically or
> +dynamically.  Probably both cases need to be supported eventually.
Would it be configurable options? It seems weird if both are applied
in the same deployment.

> +
> +*** Static IP to MAC binding
> +
> +Commonly, for a VM, the binding of an IP address to a MAC is known
It might be multiple  IP addresses binding to a port.

> +statically.  The Logical_Port table in the OVN_Northbound schema can
> +be revised to make these bindings known.  Then ovn-northd can
Would ovn-sb schema also need to be involved?

> +integrate the bindings into the logical router flow table.
> +(ovn-northd can also integrate them into the logical switch flow table
> +to terminate ARP requests from VIFs.)
> +

This would be a very interesting feature. But would it become scaling
bottleneck if each HV need to be programmed to hold all the logical
router flows (because it doesn't know whom could it be talking to)?
Or would it be a reactive approach that when the first ARP is
initiated from a VIF, the local controller request the ovn-sb DB for
the related logical router path?

Best regards,

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