[fastd] try null@l2tp method
Using null@l2tp for new installations or migrating is recommendend. This should increase bandwidth "significantly".
https://fastd.readthedocs.io/en/stable/releases/v22.html#new-features
The debian package for the gateways is currently only available in debian experimetal. https://tracker.debian.org/pkg/fastd
but i think we can pull in experimental packages the same way we're pulling bird2 from unstable. https://git.luebeck.freifunk.net/FreifunkLuebeck/gateway-config/src/branch/master/roles/base/files/etc/apt/preferences.d/unstable.pref
Some important files for adding support: