[SOLVED] VM Network Performance running PFSense/OPNSense virtualised.

adamdb

New Member
Jul 24, 2026
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Hi,
I'm new to Proxmox and thought I'd attempt to virtualise my existing PFSense firewall (currently running on a T630 thin client). I successfully deployed this on Proxmox (v 9.2.5). I also spun up the latest version of OPNSense. The issue I am having is that both seem to suffer from poor network speed and are topping out at around 90Mbits/sec download. Proxmox is running on a Lenovo 920Q micro server (i5-8500t, NVME disk, 16GB DDR Ram, Intel I350-4 4 port gigabit card). Each of the VM's is configured with a min of 8GB of RAM and 4 cores (they don't run at the same time obviously). They are both based on versions of FreeBSD (PFSense on V14 and OPNSense on OPNSense on V13 I believe). Guest OS is set to Linux (7x) CPU Host type is set to host on both the expose the hardware to the vm. The network cards for each VM (one for LAN and one for WAN) are virtIO with multi queue enabled to match the number of cores allocated. At the vm level I've turned off things like tcp offload, meltdown mitigation (advice from OPNSense forum). Ballooning is disabled.

It seems whatever I try the speed does not change. I'm pretty confident even one core on this CPU should be able to handle a pppoe connection (75mbit up/500mbit down). I've checked the pppoe log between the hardware T630 and the VM's and they negotiate the same settings so i don't think it's a upstream issue.

I know many people will have done exactly this on similar hardware so what am i missing here. Having tweaked just about everything I can find on the vm's, I'm wondering if there's some other fundamental setting I need to make in proxmox to fix this.



Any advice appreciated


<< EDIT - issue resolved. I decided to check the negotiated speed on the WAN link within proxmox. And it was 100mbs. Swapped over the patch cable and now at 1000mbs full duplex. so it turns out to be a bad patch cable!! >>
 
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