[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:

1. Change OPNsense LAN IP to 192.168.2.1
2. Assign VLAN 30 to Proxmox (192.168.30.1)
3. 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!

 

[bugacha]

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.

So your Proxmox can have IP in vlan03 (say 192.168.30.2) and will be accessible from Devs

If you want to access Opnsense from vlan03, Opnsense must have IP in that vlan as well. You can create a vlan03 interface and assign IP 192.168.30.3

This way both Proxmox and Opnsense will be accessible from Devs

 

[Think3108]

Thanks for the suggestion!

Just to clarify—if my PC gets a DHCP IP from my ISP’s AIO modem (e.g., 192.168.18.125), will I still be able to access both the OPNsense interface (192.168.2.1) and Proxmox (VLAN 192.168.30.2)?

Since my ISP modem is on the 192.168.18.x network, would I need to configure specific firewall rules or NAT on OPNsense to allow access from the WAN side to VLAN03? Or would this setup only allow access from devices already in the Devs VLAN (192.168.30.x)?

Just trying to make sure I don’t lock myself out! Thanks again.