New Install - Transparent Filtering Bridge Firewall

[Noctur]

I tried this several years ago following the Wiki official instructions without success. Searching the forum for updated information I find others are having the same issue still, some posts from as far back as 2018 asking for guidance without replies.

Does transparent firewall work? If so, is there a clear set of instructions on how to successfully set it up? I followed the Wiki again yesterday without success. https://docs.opnsense.org/manual/how-tos/transparent_bridge.html There are some bloggers with slightly different instructions, tried a couple, still no success.

My goal is set up an OPNsense appliance between the modem and wifi router in home env for IPS/IDS. TIA

[Patrick M. Hausen]

Does the router establish a PPPoE session over the modem? In that case - no chance. Transparent bridging will only work for Ethernet connections, i.e. static or DHCP.

If the latter is the case with your provider, we will probably need some more details.

[Noctur]

Hi PMHausen,

Thank you for replying...

No PPPoE, Comcast provider 1gb dn/40mb up. DHCP to Netgear CM1200 modem. AX88U wifi router. I'm trying to drop the transparent firewall between the Netgear modem and AX88U router. My appliance is DELL SFF pc, SSD, 2x add-in NICs totalling 4 eth (eventually want to link-agg). OPNsense 21.1 installed on SSD.

Currently have IP-SEC firewall script running on router, but it just can't keep up at 1gb.

Recommendations? TIA

[Patrick M. Hausen]

I would start with creating a bridge over two interfaces according to the documentation and disable all firewalling. You should be able to drop this between your devices and not notice anything.

[Noctur]

OK, thank you for your advice. I'll give it another try.