But it's not necessarily a bad idea. It depends on the circumstances, even when traversing a public network.
VXLAN is L2-like tranport over L3
You can have EoIP over WG with any VLANs you like.
You can have a VXLAN over plain IP, over EoIP, over WG, over IPSec. Only WG and IPSec (with not NULL sec) do providecany semblance ofvencryption in transit
And mandatory X\Y problem.
IPSec-equivalent, VXLAN-equivalent, IPSec-equivalent.
Prevents any compromised layer from knowing too much about the traffic.
How deranged would it be to have every nfs client establish a wireguard tunnel and only have nfs traffic go through the tunnel?
Others mentioned tailscale, it's cool and all but you don't always need it.
As far as security, that's not even the consideration I had in mind, sure wireguard is secure, but that's not why you should have vxlan inside it, you should do so because that's the purpose of wireguard, to connect networks securely across security/trust boundaries. it doesn't even matter if the other protocol is also wireguard, or ssh or whatever, if it is an option, wireguard is always the outermost protocol, if not then ipsec, openvpn,softether,etc..whatever is your choice of secure overlay network protocol gets to be the tunnel protocol.
I use Tinc as a daily driver (for personal things) and have yet to come up with a new equivalent, given that I probably should. Does Vxlan help here?
IPSec over VXLAN is what I recommend if you are doing 10G or above. There is a much higher performance ceiling than WireGuard with IPSec via hardware firewalls. WireGuard is comparatively quite slow performance-wise. Noting Tailscale, since it has been mentioned, has comparatively extremely slow performance.
I considered dropping my root wireguard and setting up just vxlan and flannel, but as I need NAT hole punching I kind of need the wireguard root so that is why i ended up with it.
Going Wireguard inside the vxlan (flannel) in my case, would likely be overkill, unless I wanted my traffic between nodes between regions to be separated from other peers on the network, not sure where that would be useful. It is an easy way of blocking out a peer however, but that could just as well be solved on the "root" wireguard node.
There might be some MTU things that would be messed up going nested wireguard networks.