Re: [PATCH net-next v7] selftests: net: add tests for PPP

[Qingfang Deng]

Hi Paolo and Jakub,

On Thu, Apr 2, 2026 at 5:48 PM Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
> Note that similar failures in the past in other test-cases were usually
> due to timing issues. i.e. the pppoe-server starts in background too
> late for the client.

I don't think it is a timing issue, otherwise the PADI negotiation
won't succeed. The "updetach" option on the client side also make it
wait for the negotiation.
It's likely that the pppd instance spawned by pppoe-server fails to
find the "rp-pppoe.so" plugin, so the connection fails when handing
off the session from pppoe-server to pppd. Note the naming difference:
the client loads "pppoe.so", while the server loads "rp-pppoe.so" by
default.

What distro do you run CI tests on? On Ubuntu 24.04, "rp-pppoe.so" is
a symlink to "pppoe.so" in apt package "ppp". Maybe an additional
package is required for the distro you use, or I may work around that
by manually creating the symlink.