pppoe problem

Hi Support,

I have problem with pppoe dialer. We use firmware 2.02.
From Syslog :

Jan 1 07:25:47 Cambium-STA kernel: VAP device ath0 created
Jan 1 07:25:48 Cambium-STA pppd[9084]: Interface ath0.2841 has MTU of 1492 – should be 1500. You may have serious connection problems.
Jan 1 07:25:49 Cambium-STA pppd[9163]: invalid numeric parameter ‘mru’ for mtu option
Jan 1 07:26:04 Cambium-STA pppd[9084]: Unable to complete PPPoE Discovery

Any idea ?

1 Like


Can you verify the MTU option for your PPPoE setup? You may have entered an invalid entry for the mtu option.

Hi to all,
I have similar problem and I have resolved with this setup:

AP with MTU = 1500 bridge mode

SU with eth MTU =1492 and wlan MTU = 1480

My PPPOE server have MTU = 1480

Maximum speed reached is 12/13 MBits up and down direction.

Same problem, same error message, but other clients with same firmware and similar configuration work.


The MTU error is misleading since PPPoE only supports up to 1492 bytes. This error has been removed from newer versions of software. If you are still running version 2.0.2, you may want to consider upgrading your devices. We have published an article in the Knowledge Base on troubleshooting PPPoE issues: