[Babel-users] V4-via-v6, which Linux kernel patches for OpenWrt 22.03?

[Juliusz Chroboczek]

Hi Linus!

> Regarding [0] does anyone have an overview of which Linux kernel
> patches might need backporting when trying this v4-via-v6 feature
> of Babel on OpenWrt 22.03's Linux 5.10 kernel?

Toke will correct me if I'm wrong, but as far as I'm aware, it's just this:

  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=321827477360

You're also going to need to manually enable it in babeld, which by
default will disable v4-via-v6 on older kernels.  See the description of
the "v4-via-v6" option in the manual page, and see also this horror:

  https://github.com/jech/babeld/blob/master/kernel_netlink.c#L962

> Sounds like it would be a lot easier, simpler approach to also get IPv4
> support with babeld+l3roamd into Gluon than the XLAT approach that was
> tried there before [1].

I'd be thrilled if you tried it and reported your experience.  We don't
currently have any operational experience with v4-via-v6.

Thanks for your interest,

-- Juliusz