Unnumbered PPPoE

[neik2]

Does OPNsense support unnumbered PPPoE interfaces? I have a business DSL connection with a subnet. I need the WAN interface to be a PPPoE connection to a modem and the LAN interface to be an IP on the subnet my ISP gives me. So the WAN interface does not have an IP address.

[bartjsmit]

Where does the PPP tunnel terminate? Why can't OPNsense not name the interface whatever it likes? The local name is not part of the connection protocol.

The DSL line normally uses ATM to communicate with the telephone exchange and runs PPPoA on top of that to provide a connection to the ISP PPP server. If the modem is capable of a layer 2 bridge between PPPoA on the DSL side and PPPoE on the Ethernet side (so-called bridging mode) then you can run a PPPoE tunnel in OPNsense and have it communicate directly with the PPP server to set up a tunnel to the wider internet.

Bart...

[neik2]

Where does the PPP tunnel terminate? Why can't OPNsense not name the interface whatever it likes? The local name is not part of the connection protocol.

Unnumbered not unnamed.

[bartjsmit]

Do you mean an interface without an IP address? https://docs.opnsense.org/manual/how-tos/transparent_bridge.html

Bart...

[neik2]

Interface without an IP address: yes, bridge: no. It's routable, the target device of my default route.

[bartjsmit]

I'm not sure that is possible. Routing is a layer 3 operation and you need an IP address for it. If you want to connect on layer 2 only, then you need a bridge is your only option.

Do you have an existing device that works this way? If so, do you get the IP address from your ISP network on the whatismyip.com website when you use it?

Bart...