VXLAN port not open in Hyper-V

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Hi,

I'm trying to get instances in a Windows Server 2016 Datacenter based Hyper-V compute node to communicate with instances on other hypervisors using Open vSwitch and neutron-ovs-agent over VXLAN. My other hypervisors run CentOS/KVM. Instances on the Linux machines can communicate just fine, but I don't get the ones running in Hyper-V to communicate with the world outside the hypervisor.

The setup runs two controller nodes (10.60.11.21 and 10.60.11.22 with a shared VIP 10.60.11.201) with the L3-agent running the router on .21. In addition I have two separate hypervisors installed, one KVM (10.60.11.23) and one Hyper-V (10.60.11.25).

The Hyper-V host runs 3 VMs, one CirrOS (192.168.0.7) and two Windows Server (one with 192.168.0.12 and one trying to use DHCP).

I have created a Hyper-V VMswitch named "external" and enabled the Open vSwitch extension. The VMswitch is connected to a physical interface named "Tenant" (without IP). I have also manually created a Open vSwitch bridge named "br-ex" and connected the "Tenant" port above to it. The hypervisor also has a Management interface with IP (i.e. 10.60.11.25) with connectivity to the other Openstack nodes, this is the interface that should be used for the VXLAN traffic.

The VMs on Hyper-V can ping themselves and other VMs on the same Hyper-V host. They can not access the router, DHCP-server on the controller node or VMs on other hypervisors.

I think the problem has something to do with that Open vSwitch does not open a listening socket for VXLAN (udp/4789), i.e. according to netstat -na | find "4789". I also can see outgoing flood traffic from br-tun to each VXLAN port according to ovs-ofctl dump-flows br-tun but I don't see this traffic in wireshark or at the incoming br-tun VXLAN port on the other hypervisors, my guess is that this is outgoing ARP requests that for some reason are not sent out on the physical interface.

If I try to connect to an instance on the Hyper-V host from the outside (10.20.150.115) I see the incoming TCP SYN on the Hyper-V host (but not on the VM).

Frame 1195965: 128 bytes on wire (1024 bits), 128 bytes captured (1024 bits) on interface 0
Ethernet II, Src: HewlettP_70:57:80 (ac:16:2d:70:57:80), Dst: HewlettP_70:a9:d0 (ac:16:2d:70:a9:d0)
Internet Protocol Version 4, Src: 10.60.11.21, Dst: 10.60.11.25
User Datagram Protocol, Src Port: 44982, Dst Port: 4789
Virtual eXtensible Local Area Network
Ethernet II, Src: fa:16:3e:e2:06:b1 (fa:16:3e:e2:06:b1), Dst: fa:16:3e:9e:f7:c6 (fa:16:3e:9e:f7:c6)
Internet Protocol Version 4, Src: 10.20.150.115, Dst: 192.168.0.12
Transmission Control Protocol, Src Port: 53839, Dst Port: 22, Seq: 0, Len: 0

I.e ... (more)