Subject: Re: [PATCH net-next] selftests: net: add tests for PPPoL2TP

From: Felix Maurer <[email-masked]>
Date: Wed, 13 May 2026 17:55:49 +0200

On Sat, May 09, 2026 at 09:13:58AM +0800, Qingfang Deng wrote:
> On 2026/5/9 1:26, Felix Maurer wrote:
> > Is there a particular reason to create the test setup with a netkit pair
> > instead of the more standard veth pairs?
>
> L2TP does not need an outer ethernet header so I choose netkit instead of
> veth.

I see, thanks. In my opinion, sticking to the same environment setup for
as many selftests as possible, i.e., using veth pairs everywhere, has
more benefits in terms of maintenance of the test than leaving out the
ethernet header has. Also, while I understand that selftests are only
supported on systems that run with the respective selftest kernel
config, I still think it's good to stick to veth as it is probably
available in more kernel builds (think resource constrained
envrionments, older kernel versions, etc.).

But in the end, it's up to you and the maintainers. However, if you
stick with netkit, please name the interfaces explicitly and don't rely
on the current auto-assigned name of the peer interface.

Thanks,
   Felix