Hello!

I'm trying to set up Guix on my "router", but I'm not able to get my networking
setup to work. What I need is one upstream NIC, and one downstream NIC which is
split into multiple VLANs.

I've tried to different approaches:

1. Have everything inside of one `static-networking` form.
2. Have one `static-networking` form for each VLAN.

If I specify multiple `static-networking` forms I get the error "guix system:
error: service 'networking' provided more than once".

If I instead put them all in the same `static-networking` form, at least the
system happily reconfigures, but I instead get failures of the networking
service.

I found one example of a more advanced networking config in the devel version of
the manual, but this one does not show multiple VLANs, but it does show multiple
links in the same `static-networking` to build a bond interface.

So, what is the correct way to setup a multi NIC networking with multiple VLANs?