Massive packet drops with SDN installed

[alexander@h]

Hi!

I am trying to get this to work for the last ~10 hours ... it is driving me realy crazy:

Setup:
- 2 dedicated Server nodes at Hetzner (1 Gbit link) located in the same DC, third node qdevice for quorum
- 1 NIC each (only public IP) -> latency between nodes: 0,3ms
- Proxmox 7.0-13 with SDN enabled (VXLAN between public NICs)

Problem:
After a few packets passed, every traffic gets dropped when having SDN installed. Even two VMs on the same vbmr1 oder on the same vnet1 are not getting throughput.

- PING works: node1 <--> node2
- iperf3 shows a few bytes in the beginning but then drops all (shows 0.00 Bytes 0.00 bits/sec)

Screenshot: iperf between two VMs on the same node connected to the same vnet1 or the same vmbr1, same result, but ping works! When migrating one vm to another node1, the same result: no throughput, but ping works (both over the VXLAN)



I have no idea anymore ...

SDN settings:

root@node2:~# cat /etc/pve/sdn/vnets.cfg
vnet: vnet1
        zone vxlan
        tag 1
        vlanaware 1

root@node2:~# cat /etc/pve/sdn/zones.cfg
vxlan: vxlan
        peers X.X.X.X,X.X.X.Y   # public node ips
        ipam pve

Find the full anonymzed system report attached.

 

[spirit]

do you have reduce mtu to 1450 inside your vms ?

 

[alexander@h]

Oh ... i thought i already tried all that ... i set the mtu in the guests to 1450 and now it works ...