Hello,
I have an environment with oVirt 4.3.8.
All seems ok from a configuration point of view, but if I use OVN based interfaces on two VMs, they are not able to ping, both if I put them on the same host and if I put on different hosts.
At this point they are both running on the same host and their only vnic is on ovn172 network (defined as 192.168.172.0/24).
I have this

manager
# ovn-nbctl show
switch fc2fc4e8-ff71-4ec3-ba03-536a870cd483 (ovirt-ovn192-1e252228-ade7-47c8-acda-5209be358fcf)
switch 87012fa6-ffaa-4fb0-bd91-b3eb7c0a2fc1 (ovirt-ovn193-d43a7928-0dc8-49d3-8755-5d766dff821a)
    port 8141047d-10c0-41f6-bedc-130552a115ef
        addresses: ["00:1a:4a:17:01:54 dynamic"]
    port 90559419-cb8e-45ae-ad61-6c16c4aff598
        addresses: ["00:1a:4a:17:01:52 dynamic"]
    port b3db190f-086a-4c79-99a0-77f811f66c80
        addresses: ["00:1a:4a:17:01:53 dynamic"]
switch 9e77163a-c4e4-4abf-a554-0388e6b5e4ce (ovirt-ovn172-4ac7ba24-aad5-432d-b1d2-672eaeea7d63)
    port 3641cae4-18df-4fba-a2bd-7b0c60a87162
        addresses: ["00:1a:4a:19:01:59 dynamic"]
    port aaddc425-3a38-49bf-bfc7-9eaeab82906e
        addresses: ["00:1a:4a:19:01:58 dynamic"]

The two macs correspond to what I see for VMs in web admin gui and at os level of the two VMs.

On the host where VMs are running I have:
# ovs-vsctl show
f1a41e9c-16fb-4aa2-a386-2f366ade4d3c
    Bridge br-int
        fail_mode: secure
        Port "ovn-b8872a-0"
            Interface "ovn-b8872a-0"
                type: geneve
                options: {csum="true", key=flow, remote_ip="10.4.192.34"}
        Port br-int
            Interface br-int
                type: internal
        Port "vnet0"
            Interface "vnet0"
        Port "ovn-1dce5b-0"
            Interface "ovn-1dce5b-0"
                type: geneve
                options: {csum="true", key=flow, remote_ip="10.4.192.32"}
        Port "vnet1"
            Interface "vnet1"
    ovs_version: "2.11.0"

So apparently I see the vnet0 and vnet1 ports associated with the two VMs
How can I check more in depth the reason why they don't ping?
Both VMs are CentOS 8.1 but I don't know if it is relevant.

Thanks,
Gianluca