pppoe MTU not being set correctly.

[franco]

> Are we saying I can now remove/unassign that superfluous interface and if I set the MTU in PPP advanced settings it will force/honour the correct MTU for the hardware interface?

The PPPoE device MTU is used verbatim now, yes. You put the one you want on the PPPoE connection and the default is 1492. Anything bigger is already "jumbo". But it will not adjust parent MTU required for jumbo scenarios.

That latter part is fixed in the development version and as stated above not yet shipped in 23.7.x, but feel free to try the development release type from the firmware settings... and in this case you can ignore the PPPoE advanced setting for MTU like before.


Cheers,
Franco

[Taunt9930]

Got it, thanks.

Apologies I missed the 'expanding/fixing' parent interface MTU automatically/invisibly to accommodate the PPPoE MTU+Header was in a future release. I'll sit tight, but sounds good [emoji106]

(WAF will not allow me to play with development builds [emoji23])

Sent from my SM-S918B using Tapatalk

[franco]

Ok no worries. We will get there :)

[keropiko]

Hello all,

for me the problem remains, i have opnsense in a vm in proxmox with proxmox MTU 9000 on the HW interface and i use VIRTIO for opnsense.

I have a "WANRAW" parent interface set to 1512 MTU, the WAN interface with 1508 MTU and since version 23.7 when mtu started to be 1492, although now i have updated to 23.7.3, after reboot the MTU is 1492.

If i change any setting on the wan interface and press "save", then the MTU goes to 1500.

[franco]

To avoid chasing shadows it would be good to confirm/deny on the development version. As I said I haven't pushed all patches and I don't know all side effects that mpd5/kernel are imposing.

I can only attest (and it was confirmed) that the code does set it correctly when invoked so something else is happening or the relevant log errors are not posted.


Cheers,
Franco

[keropiko]

Hello franco,

I am NOT on developement version, normal community edition. As i mentioned, if i just press save without any change to any of the Wan interface or to the PPPoE device, the PPPoE connection gets renewed with MTU 1500. But if i reboot, it starts with 1492.

Which logs should i post?

Thank you

[franco]

# opnsense-log | grep ifconfig


Cheers,
Franco

[keropiko]

Hi Franco ,

thank you for the reply.

the command "opnsense-log | grep ifconfig" returns empty. no results.
this is what i get with the ifconfig command:

Code Select Expand

root@OPNsense:~ # ifconfig | grep mtu
vtnet0: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet1: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet2: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet3: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet4: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1508
vtnet5: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
vtnet6: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000
vtnet7: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet8: flags=8822<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
vtnet9: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet10: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet11: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet12: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet13: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet14: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
vtnet15: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 65520
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
enc0: flags=0<> metric 0 mtu 1536
pflog0: flags=20100<PROMISC,PPROMISC> metric 0 mtu 33160
pfsync0: flags=0<> metric 0 mtu 1500
pppoe0: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> metric 0 mtu                                                                                                              1492
ovpnc1: flags=8010<POINTOPOINT,MULTICAST> metric 0 mtu 1500
ovpnc2: flags=8010<POINTOPOINT,MULTICAST> metric 0 mtu 1500
zt55cpnf57tvnd5: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 5000                                                                                                              mtu 2800
wg1: flags=80c1<UP,RUNNING,NOARP,MULTICAST> metric 0 mtu 1420
wg0: flags=80c1<UP,RUNNING,NOARP,MULTICAST> metric 0 mtu 1420
wg3: flags=80c1<UP,RUNNING,NOARP,MULTICAST> metric 0 mtu 1420


[franco]

I've made a backport of the patch for 23.7.3:

https://forum.opnsense.org/index.php?topic=21207.msg174409#msg174409

Is pppoe0 is on top of vtnet5? Maybe vtnet driver is fishy in this regard.


Cheers,
Franco

[keropiko]

hi,

pppoe is on top of vtnet4.

thank you. will look at the backport patch.

[keropiko]

------update-------

applied the patch and now the pppoe mtu after reboot is set to 1500  :D

The backport patch is from the development version or the pre 23.7 version? (Just curious)

thank you franco.