pfSense Enable L2TP Interface when PPOE Interface goes down

cwager990 · Apr 5, 2022, 1:01 PM

Good Afternoon,

I am wondering if anyone may be able to help me.

I have a configuration that allows me to connect to my ISP's BRAS via L2TP over a third-party connection if my DSL Circuit is down.

The problem is I need to be able to make pfSense bring the L2TP Interface up when the PPOE Interface goes down, this is because they cannot both be connected to the ISP at the same time.

Can anyone think of a way to automate the detection of the PPOE interface being down and then raise the L2TP Interface?

Thanks
Chris

stephenw10 · Apr 5, 2022, 2:34 PM

Not any way I'm aware of.

I could imagine doing that would prevent the PPPoE connection re-establishing too. Unless the PPPoE parent NIC goes down it would have no way to know if the PPPoE session could be re-stablished or not. And most PPPoE failures are upstream of the modem meaning the NIC would remain UP.

Steve

cwager990 · Apr 5, 2022, 9:41 PM

@stephenw10, I don't want to down the PPoE Interface what I want to do is bring up an L2TP Interface if the PPP Session on PPoE is disconnected, leaving the PPoE Interface up, and then when PPoE reconnects bring it down the L2TP Interface. It may well be impossible.

stephenw10 · Apr 5, 2022, 9:52 PM

Well there's no way to do it in pfSense directly, you'd need to add your own custom scripts.

But I can;t see how the PPPoE session could reconnect if the L2TP is up and only one can connect at a time. Unless the PPPoE auth with replace the existing login at the remote side?

Steve

cwager990 · Apr 5, 2022, 10:15 PM

@stephenw10 I have explained this badly, they can both connect at the same time, but L2TP takes routing priority on the remote side, so if they both come up they both get the same IP and therefore no traffic, but both can connect authenticate and receive the IP from the remote side at the same time.

stephenw10 · Apr 5, 2022, 11:22 PM

Ah, OK. Well in that case you could potentially create a failover gateway group with the two WANs. But I could imagine it would get stuck on the L2TP WAN. You would need to configure the L2TP WAN to be dial-on-demand and disable monitoring etc so it closed the link. But That would take far too long. Also I could imagine the PPPoE monitoring might fail until the L2TP disconnects.

It seems like you could script it though. Probably take a bit of testing to find the right rc calls to work with those.

Steve