Hello,
I have a weired issue and I wonder if I can have messed up my switch in anyway. CRS309-1G-8S+IN switch which I run swos 2.13 on.

My issue is that I have 2 proxmox hosts and I get line speed if I run iperf3 --bidir on the actual hosts. But If I run the same on 2 vm's on a VLAN I get line speed one direction but half the speed in other. Running out of ideas and just wonder if you know of anyway I could have missconfigured switch? From what I remember the only thing I have done is adding VLANS to it.

Example iperf3 output host to host:

[ 5][TX-C] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 144 sender
[ 5][TX-C] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec receiver
[ 7][RX-C] 0.00-10.00 sec 10.9 GBytes 9.37 Gbits/sec 1150 sender
[ 7][RX-C] 0.00-10.00 sec 10.9 GBytes 9.37 Gbits/sec receiver

Between VM's on a VLAN, one vm on each proxmox host:

[ 5][TX-C] 0.00-10.00 sec 5.62 GBytes 4.83 Gbits/sec 964 sender
[ 5][TX-C] 0.00-10.00 sec 5.62 GBytes 4.83 Gbits/sec receiver
[ 7][RX-C] 0.00-10.00 sec 10.8 GBytes 9.31 Gbits/sec 25699 sender
[ 7][RX-C] 0.00-10.00 sec 10.8 GBytes 9.30 Gbits/sec receiver

May not be related to switch at all but I have just run out of ideas. Would be more logical if speed was bad both ways.

It would be logical that if physical hosts can do wirespeed and there's nothing in config of switches specific to MAC addresses, that also virtual hosts on same physical hosts would be capable of doing wirespeed. As this is not the case, I'd look at VM layer for any funky config (proxmox is acting as another switch after all). Look into selection of virtual NIC type and play with that, some behave better than others. And that's an interaction between virtual hardware (provided by virtualization engine) and driver (inside virtual server).

Hello,
the only reason why I suspect switch was because I took my workstation and installed proxmox and created a VM on VLAN. This VM could get linespeed both ways to both vm's on the two old proxmox hosts.

SWOS has learning configured on all VLAN's which is default which is what I assume populate static hosts list. The same is true for the Linux bridges since it's default.

Have a 4 port Mikrotik switch, will test that tonight and see if it makes any difference. Although it also runs Swos.