Our small business uses a Sonciwall TZ210 on a fixed IP line in our office, subnet for this location is 192.168.3.0. This is connected to a Draytek 2850 router at my home address using an IPSec VPN tunnel, local subnet is 192.168.1.0.
I have a FreeNAS file server set up at my home address that hosts some files and stores backups. Out of necessity I now need to provide one of our suppliers with access to a file the sits on the FreeNAS box at my home address using SSH.
My intention is to use the public IP address of the router at the office to provide SSH access to the private server at the home address.
I have followed instructions on Sonicwall's site to configure the TZ210 to allow traffic from the WAN zone to the VPN zone for this service, and secondly to translate the source traffic from a WAN IP to a LAN IP so that it can traverse the VPN tunnel.
Whatever I try, the connection is refused when attempting to connect from the WAN zone. I can however access the server using the public IP address of the router from an office-based PC on the 192.168.3.0 subnet with a suitable NAT policy set up, however the auth log on the server does not show the translated IP (which should be the router), it shows its actual private address. With no NAT policy it doesn't work at all from that location.
I'd like to know if I'm missing any setup steps to get this working, or whether I've misconfigured something. I'm convinced there is an issue with NAT because the server log shows the original IP rather than the translated IP, but I don't understand why.
Pictures of both the NAT policy and firewall policy attached. Any help is appreciated.