What routing protocol does Incus use for "peer routing relationships" with "Isolated OVN Networks" on multiple other Server Nodes

[bmullan (Brian Mullan)]

I have started looking into use of Geneve with Incus and have a question after reading this thread on the forum:

Isolated OVN Network

There was a comment which said:

@lpribeiro

Hello Stéphane, thanks a lot for sharing this information. It helped understanding OVN. I think is good to let the incus manage all the address space, and with this I come with a question:
if I create a bridge (normally /24), and we create several OVN networks (of course will be limited to maybe 252 IPs for the routers of the OVN networks), if we create another bridge and use that new to create more OVN networks, can we connect two OVN networks in different bridges using: peer routing relationships like in the doc: How to create peer routing relationships - Incus documentation

So I looked up “peer routing relationships” In the Incus documentation and there is a section:

How to create peer routing relationships

which further says:

Create a routing relationship between networks

To add a peer routing relationship between two networks, you must
create a network peering for both networks. The relationship must
be mutual.

If you set it up on only one network, the routing relationship
will be in pending state, but not active.

When creating the peer routing relationship, specify a peering
name that identifies the relationship for the respective network.

The name can be chosen freely, and you can use it later to edit
or delete the relationship.

So my question is…

What protocol does Incus use for this “routing”… BGP, OSPF, EIGRP ?

None of the cli command examples I’ve seen specify any routing protocol?

I know Incus supports BGP as a server… so is BGP the routing protocol described above?

thanks

[osch]

As far as know this is all OVN specific functionality Incus is using.

From memory the feature is called OVN Interconnection that needs to be configured or better is configured by Incus. It is only required if you want to connect two OVN network across different data center or like the case you pointed out where there are more than 252 networks on one bridge.

OVN handles all the routing etc. and talks TCP between the OVN networks. Works pretty well for me connecting multiple networks on different sides of the globe.

[bmullan (Brian Mullan)]

@osch Thanks for mentioning & the link to “OVN Interconnection”! That explained alot.

The Incus documentation section I previously mentioned just says:

Therefore, Incus allows creating peer routing relationships between two OVN networks. Using this method, traffic between the two networks can go directly from one OVN network to the other and thus stays within the OVN subsystem, rather than transiting through the uplink network.

It didn’t say how or what actually does that functionality but the way it is worded somewhat implies Incus itself is doing some magic on its own to accomplish it.

[osch]

The magic is that Incus takes the complexity away and just performs all the OVN calls in the backend.

In general Incus is the management layer which takes care about all the different steps to maintain a working environment.