On Wed, Dec 9, 2020 at 1:33 PM Daniel Alvarez Sanchez <dalvarez@redhat.com> wrote:
Hi all,
On Wed, Dec 9, 2020 at 10:56 AM Thomas Goirand <zigo@debian.org> wrote:
On 12/8/20 4:12 PM, Tim Sæterøy wrote:
Hi,
I'm trying to explore BGP support when using OVN in Neutron, but haven't been able to find much info on the topic. According to [1] committed in march 2020, OVN seems to lack similar functionality as is seen in ML2/OVS, but there's no further references:
Currently ML2/OVS supports making a tenant subnet routable via BGP, and can announce host routes for both floating and fixed IP addresses.
I've tried searching for 'bgp' on Neutrons launchpad for issues tagged with 'ovn', in the 'ovn-org/ovn' repo or on docs.ovn.org, but I'm getting blanks.
Does anyone happen to know where OVN stands on this, and especially in the context of Neutron? Or perhaps able to point me in the right direction where I can find out more? Thanks.
Precisely, there is a talk scheduled for today in the OVS/OVN con about introducing BGP support in OVN [0][1] by Nutanix folks. This is more about EVPN and advertising /32 (or /128) to the router.
So far, there is nothing specific in Neutron for the ML2/OVN driver. However, neutron-dynamic-routing project would work for you with ML2/OVN to advertise tenant networks but advertising FIPs is currently relying on having 'agent gateway' ports which consume one IP per L3 agent per compute node.
s/per L3 agent per compute node/per L3 agent per provider network
This is something that ML2/OVN doesn't do so currently there's no way with neutron-dynamic-routing to advertise FIP host routes directly to the compute node.
Can you describe the use cases that you'd have in mind or you just wanted to know the current status?
Thanks a lot! daniel
[0] https://www.openvswitch.org/support/ovscon2020/ [1] http://www.openvswitch.org/support/ovscon2020/slides/OVS-CONF-2020-OVN-WITH-...
[1]: https://docs.openstack.org/neutron/victoria/ovn/gaps.html
-- Tim
Hi,
As much as I know, there's no upstream (ie: OpenStack without downstream modification) for BGP-to-the-host support, appart from the non-mainstream callico driver, which I haven't tested.
However, I have been able to do a kind of "bgp-to-the-rack" where the L2 networking is limited to segments on a single rack. This can be done adding this patch to Neutron:
https://review.opendev.org/c/openstack/neutron/+/669395
As you can see, I did a few iteration of this patch, but now, I've been told to add more db tests, which I don't have the skills for. I asked for more help from the Neutron team, but so far, everyone seems busy. However, I did test this, and it works kind of well. :)
If you wish to help to get this patch going in, please do! :)
Note that this doesn't use OVN. I have no idea if it would work with OVN or not (I never did such a setup, only used plain OVS).
Now, this doesn't replace a full BGP-to-the-host setup, but hopefully, the Neutron team will be able to have this done "soon" (whatever that means), as interest for it is growing.
Cheers,
Thomas Goirand (zigo)