Still unable to get 1500 mtu on pppoe on 23.7.5 no matter what I do. Why?

[allebone]

Unsure how to progress this. Tried different values and settings but pppoe is always 1492 no matter what I do.

Here are my settings. Why does it not work?

[allebone]

Second ss

[allebone]

Third ss

[allebone]

Last ss

[allebone]

Literally dont know what else to change at this point. Ss simply show my last effort to get it working but pretty sure I have tried every permutation and setting values in all different places with no effect.

[franco]

Let's make sure a manual setting somewhere is not preventing it from adjusting correctly:

# opnsense-log | grep ifconfig

It should show errors regarding setting MTU. Then we could look at the config and find those offending values.

I'd also check the PPP device settings as under advanced they also have room to set MTU again...


Cheers,
Franco

[dinguz]

I have 3 interfaces concerning internet access:

- the interfaces which runs PPPoE, this has a MTU of 1508 in the settings, which yields a MTU of 1500 on the connection
- the parent interface of this, which is the VLAN interface (MTU set to 1508)
- the parent interface thereof, which is the Ethernet interface (MTU set to 1512)

I couldn't get it to work at first, but then I figured out I needed to create the VLAN interface as an intermediate, in order to be able to set the MTU on it.

[franco]

All of this is automatic now in 23.7.5.

You just need to set the correct MTU in the WAN interface that the PPPoE is assigned to (heeding that the effective MTU on PPPoE is the "calculated" value displayed not the one entered).


Cheers,
Franco

[dinguz]

So with 23.7.5 in my case I just need to set the WAN interface to 1512 and that should be all?

[Taunt9930]

So with 23.7.5 in my case I just need to set the WAN interface to 1512 and that should be all?

Yes - set the MTU to whatever it needs to be + overheads. In my case, just 1508 on a straightforward PPPoE connection.  I have just done that, and deleted the interface I previously created from the physical interface just to set the 'parent' MTU.

All is good, with a verified MTU of 1500 on the link.

As an aside, IPv6 seems to be working much better/consistently - not sure if it is other changes, or the 'fake' interface I had to previously create was causing come issue.

[allebone]

Let's make sure a manual setting somewhere is not preventing it from adjusting correctly:

# opnsense-log | grep ifconfig

It should show errors regarding setting MTU. Then we could look at the config and find those offending values.

I'd also check the PPP device settings as under advanced they also have room to set MTU again...


Cheers,
Franco

Hi Franco,

Thank you for the reply. The output is nothing when I do this (first screenshot)

My advanced options has nothing set (second screenshot).

Kind regards
Peter

[allebone]

"You just need to set the correct MTU in the WAN interface that the PPPoE is assigned to (heeding that the effective MTU on PPPoE is the "calculated" value displayed not the one entered)."

I am not clear what to do here. I have 2 interfaces for some reason. A "dummy" interface and a normal pppoe interface.
Am I clearing the config from one of them? If so which one and where am I inputting 1512? The dummy or pppoe interface?

Or am I deleting this dummy interface and setting 1508 on the pppoe interface?

Kind regards
Peter

[JohHer]

1508 on the WAN (PPPoE) interface and e reboot ?

[staticznld]

Just updated to 23.7.5.

Deleted all dummy interfaces "Physical NIC" "VLAN", checked WAN PPPoE is set to 1508 calculated MTU is 1500.
Upgrade to 23.7.5 and voila! 1500 MTU on PPPoE

[allebone]

Just updated to 23.7.5.

Deleted all dummy interfaces "Physical NIC" "VLAN", checked WAN PPPoE is set to 1508 calculated MTU is 1500.
Upgrade to 23.7.5 and voila! 1500 MTU on PPPoE

Just tried this exact thing. Deleted PPPOEDMY so its now gone, checked that pppoeWAN had 1508 set as MTU. Calculated MTU said 1500.

Saved, rebooted. MTU under interfaces - overview still 1492. So not clear what else to do. Nothing works for me the same as other people.