Hi, We have a 6-node Proxmox cluster. Recently we updates from Proxmox 4 / Debian 8 to Proxmox 5 / Debian 9. Since the upgrade, we have many failed PfSense firewalls running as VM on Proxmox. We run every PfSense firewall with 2 adapters. 1 adapter is for WAN without a VLAN, the other adapter is for LAN with a VLAN tag. Every day, 1 or 2 PfSense VM's (we run 12 PfSense VM's) loosse their connection with the VLAN adapter (LAN). We can't ping from the LAN side servers to the PfSense. The PfSense can't ping to the LAN side servers, only WAN works. When we change the VLAN or even remove it, it has no effect. When we restart the PfSense VM, everything works again. Any idea why this happends and how to solve it?