VM port issue

[Sindreafg]

Hi!
I'm a fresh user of Proxmox trying to move some of my VM-load from Unraid to my earlier bare-metal Pfsense-router.
Almost everything is running fine, with the exception of a connection issue in one of my VMs.
My Proxmox-server currently contains a VM for Pfsense and a VM for Homeseer (home automation software running on W10).
One of my plugins is trying to connect to two arduino's via a plugin. From homeseer's log, the connection fails when trying to connect to the arduino's on port 8900.
I've disabled all the firewalls on both Proxmox and W10, but still no luck. I can also ping the IP of the arduinos just fine. On my old Unraid-VM everything is working as it should, so it has to be something with my Proxmox config. Do I have to do some port forwarding? I consider the virtual bridges as switches..

My homeseer-VM is currently connected to vmbr0, but I've also tried vmbr2 (both as linux bridge and OVS bridge), and also without the ip/subnet configured as pfsense should handle this. The VM has IP 192.168.2.18, and the arduino's 192.168.2.177 and 178.

Spoiler: interfaces

# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

auto enp3s0
iface enp3s0 inet manual

auto enp1s0f0
iface enp1s0f0 inet manual

allow-vmbr2 enp1s0f1
iface enp1s0f1 inet manual
ovs_type OVSPort
ovs_bridge vmbr2

auto vmbr0
iface vmbr0 inet static
address 192.168.2.5
netmask 255.255.255.0
gateway 192.168.2.1
bridge-ports enp3s0
bridge-stp off
bridge-fd 0

auto vmbr1
iface vmbr1 inet manual
bridge-ports enp1s0f0
bridge-stp off
bridge-fd 0
#WAN

auto vmbr2
iface vmbr2 inet static
address 192.168.2.14
netmask 255.255.255.0
ovs_type OVSBridge
ovs_ports enp1s0f1
#LAN

Spoiler: pveversion -v

root@proxmox:~# pveversion -v
proxmox-ve: 5.4-1 (running kernel: 4.15.18-13-pve)
pve-manager: 5.4-5 (running version: 5.4-5/c6fdb264)
pve-kernel-4.15: 5.4-1
pve-kernel-4.15.18-13-pve: 4.15.18-37
pve-kernel-4.15.18-12-pve: 4.15.18-36
corosync: 2.4.4-pve1
criu: 2.11.1-1~bpo90
glusterfs-client: 3.8.8-1
ksm-control-daemon: 1.2-2
libjs-extjs: 6.0.1-2
libpve-access-control: 5.1-8
libpve-apiclient-perl: 2.0-5
libpve-common-perl: 5.0-51
libpve-guest-common-perl: 2.0-20
libpve-http-server-perl: 2.0-13
libpve-storage-perl: 5.0-41
libqb0: 1.0.3-1~bpo9
lvm2: 2.02.168-pve6
lxc-pve: 3.1.0-3
lxcfs: 3.0.3-pve1
novnc-pve: 1.0.0-3
openvswitch-switch: 2.7.0-3
proxmox-widget-toolkit: 1.0-26
pve-cluster: 5.0-36
pve-container: 2.0-37
pve-docs: 5.4-2
pve-edk2-firmware: 1.20190312-1
pve-firewall: 3.0-20
pve-firmware: 2.0-6
pve-ha-manager: 2.0-9
pve-i18n: 1.1-4
pve-libspice-server1: 0.14.1-2
pve-qemu-kvm: 2.12.1-3
pve-xtermjs: 3.12.0-1
qemu-server: 5.0-50
smartmontools: 6.5+svn4324-1
spiceterm: 3.0-5
vncterm: 1.5-3
zfsutils-linux: 0.7.13-pve1~bpo2

 

[Richard]

It's unusual to have 2 (physical) interfaces connected to the same subnet (192.168.2.0/24) with independent IP addresses. However, for the VM it does not count.

Suggest to follow the IP packets from the Windows VM to the Arduinos and back. Assuming your VM-ID is 100 which has just one virtual NIC it would be in the Proxmox host:

tcpdump -e -n -i tap100i0 
tcpdump -e -n -i vmbr0 
tcpdump -e -n -i enp3s0

Inside Windows you can use wireshark for investigating packets.