[ovs-dev] [PATCH RFC ovn] Add VXLAN support for non-VTEP datapath bindings

[Numan Siddique]

(Sorry, top posting it)

Hi Ihar,

I tested out your patch. All the tests pass.

I then tested out using the ovn-fake-multinode [1].

After the deployment, I changed the encap to vxlan. East/West traffic
worked fine
without any issues.. But I was not able to ping to the gateway router port IP
from outside (172.16.0.100). The moment I changed the encap back to
geneve, the ping
works. I didn't look into the issue. So not sure what's the reason.
You may want to try out
once with ovn-fake-multinode

Thanks
Numan

[1] - https://github.com/ovn-org/ovn-fake-multinode/




On Tue, Mar 24, 2020 at 1:37 PM Numan Siddique <numans at ovn.org> wrote:
>
> On Tue, Mar 24, 2020 at 5:17 AM Ben Pfaff <blp at ovn.org> wrote:
> >
> > On Mon, Mar 23, 2020 at 06:39:14PM -0400, Ihar Hrachyshka wrote:
> > > First, some questions as to implementation (or feasibility) of several
> > > todo items in my list for the patch.
> > >
> > > 1) I initially thought that, because VXLAN would have limited space
> > > for both networks and ports in its VNI, the encap type would not be
> > > able to support as many of both as Geneve / STT, and so we would need
> > > to enforce the limit programmatically somehow. But in OVN context, is
> > > it even doable? North DB resources may be created before any chassis
> > > are registered; once a chassis that is VXLAN only joins, it's too late
> > > to forbid the spilling resources from existence (though it may be a
> > > good time to detect this condition and perhaps fail to register the
> > > chassis / configure flow tables). How do we want to handle this case?
> > > Do we fail to start VXLAN configured ovn-controller when too many
> > > networks / ports per network created? Do we forbid creating too many
> > > resources when a chassis is registered that is VXLAN only? Both? Or do
> > > we leave it up to the deployment / CMS to control the chassis / north
> > > DB configuration?
> > >
> > > 2) Similar to the issue above, I originally planned to forbid using
> > > ACLs relying on ingress port when a VXLAN chassis is involved (because
> > > the VNI won't carry the information). I believe the approach should be
> > > similar to how we choose to handle the issue with the maximum number
> > > of resources, described above.
> > >
> > > I am new to OVN so maybe there are existing examples for such
> > > situations already that I could get inspiration from. Let me know what
> > > you think.
> >
> > I don't have good solutions for the above resource limit problems.  We
> > designed OVN so that this kind of resource limit wouldn't be a problem
> > in practice, so we didn't think through what would happen if the limits
> > suddenly became more stringent.
> >
> > I think that it falls upon the CMS by default.
>
> I agree. I think It should be handled by CMS.
>
> Thanks
> Numan
>
> >
> > > > > Assuming we pick a term to use to describe these out-of-cluster
> > > > > switches, we should consider the impact of the rename. Renaming
> > > > > internal symbols / functions is trivial. But "vtep" is used in OVN
> > > > > schema (for example, for port binding 'type' attribute). Do we want to
> > > > > rename those too? If so, what considerations should we apply when
> > > > > doing it? Any guidance as to maintaining backwards compatibility?
> > > > >
> > > > > Also, is such a rename something that should happen at the same moment
> > > > > when we add support for VXLAN for in-cluster communication? Or should
> > > > > it be a separate work item? (If so, do we expect it to land before or
> > > > > after the core VXLAN implementation lands?)
> > > >
> > > > We can't (or at any rate should not) change the terms in the schema, but
> > > > we can change other places and point out to people in a few places that
> > > > a "ramp switch" is sometimes, confusingly, called a "vtep".
> > >
> > > Gotcha. Any preferences as to whether to consider it a preparatory
> > > work item; a follow-up; or a part of the VXLAN implementation? (I lean
> > > towards handling the ramp term introduction as an independent
> > > preparatory step.)
> >
> > I sent out a patch for people to look at.
> > _______________________________________________
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> >