UK PPPoE FTTP (Zen)

[Taunt9930]

Hi All,

Is anyone using Zen as an ISP, or any other PPPoE provider in the UK? I have successfully configured my connection using the wizard, and all is working well. However, the tinkerer in me wants to set a 1500MTU on the WAN Connection (out of principle lol) - it is supported by my ISP, and the Openreach ONT supports Jumbo frames.

From what I've seen, it should be as simple as setting Interfaces > WAN > MTU to 1500 (Thus showing underneath calculated MTU: 1500, rather than 1492). If I do that, the interface comes up, Interfaces > Overview > WAN interface (wan, pppoe0) shows an MTU of 1500, but I have broken connectivity.

Any clues, what am I missing? Where can I look?

Thanks.

[Taunt9930]

OK, so typically, I have posted and then found the answer. In case it helps others:

I SSH'd in, and did an IFConfig with a working default 1492 config. Saved it into Notepad++. I then made the change above, to create the 1500MTU PPPoE link - did an IFConfig, saved to Notepad++.

I then compared the two files - as expected, little change (in fact, too little) - the IPv4 gateway had changed, the MTU on the PPPoE link had changed to 1500. Then I noticed the Physical Interface (igb0) still had a 1500 MTU.

A bit of scratching around, and I noticed that the way PPPoE is now set up (I used the Wizard on startup, if that's relevant), you end up with the parent interface floating about 'unassigned' - still at the bottom of the assignments page, in green. If you add it as a new assigment (I called it Dummy), save it, configure nothing else except set the MTU to 1508...then it all springs into life.

Left with this on interface assignments as attached

EDIT: Seems to be the same sort of issue/observation as here, although no vlans required in my case - just straight pppoe - https://forum.opnsense.org/index.php?topic=19747.0

And I agree with the comment, I now have unnecessary 'Dummy' interfaces scattered around in Firewall section etc!