---- On Sun, Oct 18, 2026 at 5:15 PM Greg Troxel <[email protected]> wrote:
> Andreas Kähäri <[email protected]> writes: > > > I'm using a KVM virtual machine running NetBSD 11.0 (on amd64). On it, > > I'm attempting to use Restic to perform backups and related operations > > over Tailscale. When I do, I consistently get errors saying "write: > > address family not supported by protocol family". This seems to happen > > regardless of whether the machine has IPv6 networking or not (just > > mentioning that since that's not the default network setup for qemu). > > You have not explained the networking plan for your KVM vm. Is the > NetBSD (virtual) machine's interface bridged, or is it some kind of > NAT/routing? > > I am unfamiliar with tailscale details; I'd expect that to configure wg0 > but maybe it is doing user-space wireguard. $ ifconfig tun0 │ ││tun0: flags=0x51<UP,POINTOPOINT,RUNNING> mtu 1280 │ 7.0.t││ status: active │ ││ inet6 fd7a:115c:a1e0::1901:cd50/48 -> flags 0 │ ││ inet 100.73.205.61/32 -> flags 0 so, no wg0, wireguard is completely hidden from the user > > I would suggest running "ifconfig", understanding the results especially > the address, ping and traceroute to your NAS. > > Then, understand how restic uses the network (I don't know that either) > and generated that kind of traffic from client to NAS with test tools > (less complicated) and see how that goes, watching it with tcpdump. > > > You can also find the interface used and tcpdump on that. I suggest > "-wFILE" and leave it running, and then analyze later. That way you can > capture once and try different filters. > > > "write: address family not supported by protocol family" > > I have a very dim memory of this happening either when writing via bpf > or various tunnels, when they are configured for one address family and > the packet written isn't right (or is interpreted as not right). >
