[ovs-dev] [PATCH v2 1/3] ovn: Update TODO, ovn-northd flow table design, ovn-architecture for L3.

Ben Pfaff blp at nicira.com
Fri Oct 2 14:52:26 UTC 2015

On Thu, Oct 01, 2015 at 11:55:19PM -0700, Amitabha Biswas wrote:
> > On Sep 30, 2015, at 1:56 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.
> > 
> > +* L3 support
> > +
> > +** OVN_Northbound schema
> > +
> > +*** Needs to support interconnected routers
> > +
> > +It should be possible to connect one router to another, e.g. to
> > +represent a provider/tenant router relationship.  This requires
> > +an OVN_Northbound schema change.
> It’s not obvious to me what the NB schema change involved here will
> be? Will the the router ports connecting 2 routers be treated as a
> special case?

I don't know yet, figuring out a design would be the job of whoever
takes that on.  It does seem likely that they'll need to be different
because of the structure of the rest of the schema.

> > +*** Needs to support extra routes
> > +
> > +Currently a router port has a single route associated with it, but
> > +presumably we should support multiple routes.  For connections from
> > +one router to another, this doesn't seem to matter (just put more than
> > +one connection between them), but for connections between a router and
> > +a switch it might matter because a switch has only one router port.
> From an OpenStack integration point of view is this for supporting
> multiple subnets in a Logical Network? If so I would imagine this
> would involve a OVN_NB schema change for the Logical Router Port [each
> supporting multiple routes] or Logical Switches having a list of
> router ports.
> For e.g. let’s say say we have 2 subnets in one Logical Switch (LS1)
> and 1 subnet in another Logical Switch (LS2). This would requires 3
> (or 2?) “logical patch” ports pairs in the OVN_SB schema below.

This item comes from the analogy to physical networks: if I set up a
router I can add as many routes to a link as I like.  I don't have a
particular use case for it, it's just for completeness in that analogy.

More information about the dev mailing list