[Help] OPNsense + Proxmox Setup with Limited NICs – Access Issues

[Think3108]

Hey everyone,

I'm currently setting up my OPNsense firewall + Proxmox setup, but I've run into an access issue due to limited network interfaces.

My Setup:
ISP/Modem: AIO modem from ISP, interface IP: 192.168.1.1
OPNsense Firewall:
WAN (ETH0, PCI card): Connected to ISP, currently 192.168.1.1
LAN (ETH1, Motherboard port): Planned VLAN setup (192.168.30.1)
Proxmox: Still being set up, intended to be on VLAN 192.168.30.1
I only have 2 physical NICs on the OPNsense machine
The Issue:
Since I only have two NICs, how can I access both the OPNsense web UI and the Proxmox web UI once VLANs are configured? Right now, I can't reach OPNsense or Proxmox easily for management.

My Current Idea:
Change OPNsense LAN IP to 192.168.2.1
Assign VLAN 30 to Proxmox (192.168.30.1)
Access OPNsense and Proxmox via a router that supports VLANs
Would this work, or is there a better way to set this up? Any suggestions from people who have dealt with a similar setup?

Thanks in advance!

[viragomann]

I'm currently setting up my OPNsense firewall + Proxmox setup

Is this OPNsense on top of Proxmox or in front of it?

If OPNsense is in front of Proxmox, as your graphic shows, just get a VLAN-capable switch and connect it in between.

Access OPNsense and Proxmox via a router that supports VLANs

OPNsense is a router and it supports VLANs.
You need a switch to terminate the VLANs though, where you can connect all other devices to. On OPNsense you can define multiple VLANs on a single trunk NIC then.

However, I've read that Realtek NICs doesn't work well with FreeBSD and VLANs. Maybe there are special drivers available for it to get them work reliably. I'd recommend to do some further research on this before you start.

[EricPerl]

I assume we're talking about OPN as a VM under Proxmox.
I concur you also need a VLAN capable switch. 

https://forum.opnsense.org/index.php?topic=45437.msg227451#msg227451
That's a setup with just one NIC but you should be able to extrapolate for 2 NICs (1 for WAN, the other for VLANs + Proxmox).

A simpler configuration would be to leave LAN and Proxmox untagged but as soon as you want other VLANs...

[EricPerl]

Oh, and the Realtek issues under Proxmox/FreeBSD might not be a concern if you're passing the bridges to the VM.