I have an IPSec tunnel between work and home, with a pfSense firewall on both ends. The VPN works fine, although I never got DNS to work properly across sites, and I use Host Overrides in the DNS forwarder settings on both ends to be able to access remote machines by name. I only have a handful of mappings and this is managable (albeit not pretty).
Now I want to set up a QNAP NAS in my home network (behind a Cisco SG300-28P 28-Port Gigabit PoE Managed Switch) that uses the QNAP RSync backup to replicate data from a QNAP NAS at work to the one in my basement.
I would have preferred to use an IP address from the work subnet for the NAS at home, but that does not appear to work. Why not? Do I have to use an IP address in the local subnet, even though the remote domain and DNS server are always accessible? Do I need a virtual network?
Maybe this was a naive question. By using static IPs from each network and putting the home network IP into the DNS server at work the machine name resolves just fine and I can access the box across the VPN tunnel. I suppose that before a machine can use the VPN tunnel, it needs to have established itself in the local network, and this requires that it is in the local subnet and not in some foreign subnet.