[SOLVED] PPPoE gets wrong IP

[opnsense-user123]

Hello:

I'm on an Andrews & Arnold (UK) Fibre connection (uses BT backhaul). I have a connection with a certain static WAN IP but also have a routed /29. When Opnsense brings up the PPPoE connection it uses the first routeable IP of the /29 as its WAN IP address. This, and the other usable IPs are mapped as virtual IPs over the PPPoE/WAN interface. This results in nothing working, unsurprisingly. I do have a Dummy Wan interface (not PPPoE) I could perhaps try mapping the virtual IP over that interface.

When I connect my Mac computer directly to the fibre ONT and bring up the PPPoE connection, it gets the correct WAN IP every time.

I recall there used to be a function to REJECT certain IPs as the PPPoE 'leased' IP which might work, but I can't find that option anymore. Also, if I could assign Static IP to the PPPoE connection that would be fine as it won't change. But when I type that into the advance PPPoE options in OpnSense, it will start working, but the setting does not stick, just disappears and the problem will recur.

If I manually bring down and up the PPPoE connection one to two times, it will sort itself out and get the right WAN IP like the Mac did.

What can I do? Thanks.

[MoonbeamFrame]

I have an A&A fibre [CityFibre] as one of the links on an OPNsense box.

I set the PPPoE gateway to the allocated /32 [on VLAN  911 for CityFibre].

Then defined the /24 to the same physical interface and added the non-gateway addresses as virtual IP's.

HTH

[opnsense-user123]

Thanks MoonbeamFrame, I appreciate the help. Could you possibly expand a bit more on what you wrote?

Anything I type under Interfaces > Point-to-Point > Devices in either the 'Local IP' space (which requires to be a /31 or less, a /32 is impossible, so I have no idea what netmask to use here) OR the 'Gateway' space, gets blanked out after being applied (applied or ignored, I'm not sure which).

So, when you say you "set the PPPoE gateway to the allocated /32" I'm not sure where you are setting that. I agree, I'd like to do that, I would use what AAISP told me was the 'WAN' address, not any of the routed /29 addresses.

Then when you say you assigned the /24 to the same physical interface as Virtual IPs, does that mean you have the Ethernet interface showing twice in the list of interfaces, once with PPPoE over it and once without? When I referred to my Wan Dummy, that's what I meant. I had to create it to run baby-jumbo packets, which did work.

[MoonbeamFrame]

The A&A support site has a couple of pages that might help (I can see you don't need to use a VLAN).

General router page https://support.aa.net.uk/General_Router_Settings

OPNsense configuration https://support.aa.net.uk/Router_-_OPNsense

Edit:

Rather than created a dedicated PPPoE in Point-to-Point Devices, try creating the interface with an IPv4 Configuration Type of PPPoE

[opnsense-user123]

Thanks for the links.

It was all working fine before I got the additional routed IP block. The instructions state to use static routes for the routed IPs, but I haven't tried that. The Virtual IPs are working except for this PPPoE bring-up issue. IPv6 isn't working either, but that also doesn't work when I connect a computer directly to the ONT and bring up PPPoE there.

I'll keep poking at it.

[opnsense-user123]

I changed all the Virtual IPs to the [WanDummy] instead of the [PPPoE] interface and rebooted. It did come up with the right WAN address. Too early to tell if that solved the problem as it was a bit random, but it's a good sign.

[opnsense-user123]

This does seem to have solved it!