[RP-PPPoE] PPPoE MTU problem

[Dianne Skoll]

On Mon, 22 Feb 2016 10:15:21 +0800
Wenzhuo Zhang <wenzhuo at gmail.com> wrote:

> The PPPoE Access Concentrator of my ISP offers MRU values of both 1492
> and 1442. ppp-2.4.5 in Ubuntu 14.04 adopts 1492 as the MTU of the ppp
> device, while ppp-2.4.7 in Ubuntu 16.04 (xenial developement) adopts
> 1442. Choosing the lower MTU on the WAN link (ppp0) exposes users to
> the nasty PMTU-D problem, especially for remote VPN clients. I also
> reproduced the same problem in openwrt 15.05 and dd-wrt r29085, both
> of which come with ppp-2.4.7.

That's not a PPPoE problem.  It's a pppd misconfiguration; you can
easily fix it in the pppd config file.

Regards,

Dianne.