Running OPNSense inside a virtual machine with NAT causes very slow performance.
Running OPNSense inside a virtual machine with NAT causes very slow performance.
I build a Host with very capable Hardware, Core i7 3770K with 8GB of RAM and 120GB SSD Host, 120GB SSD VM, 2TB Cache As diagram below: before I put online, I was testing OPNSense NAT performance under VM, I found I couldn't achieve at least 350Mbps, I assign 2 vCPU for OPNSense alone, during iperf Test, OPNSense max out 100% CPU Usage. Currently I doing separate machine, I thought using VM can save some electricity, but performance are not satisfied
For improved performance on the NIC, consider using virtio with the virtio driver instead of the default e1000. Opt for bridged networking rather than NAT. You might also pass through an entire network card to the VM, which can make a big difference. However, I wouldn't run your router or firewall inside a VM if it manages your whole network—it's generally not a good practice to virtualize such critical components.
Your router providing alternative DNS servers works well for clients during downtime. LanCache is indeed used for Steam games, though I can't say much about it since I don't use it personally.