Hi
"As soon as I did this, the "server" on the new Static IP address became innacessible from devices on the main LAN.
Similarly the "server", now proudly boasting its new static "217.xxx" address, could no longer communicate with devices on the LAN."
Does the server have 2 network interfece cards? As the hub 3 will only apply a single IP address (either WAN or LAN) if you have two NIC's on the server you could have one hard set to the local IP and the other hard set to the WAN IP.
"In addition, a second Static IP device - a hard disk recorder - is pingeable from the internet, but refuses to respond to HTTP calls. (it has a web interface). When I turn the Business Hub 3.0 firewall off, it works. It stops working as soon as the firewall is turned back on. Port forwarding for HTTP and HTTPS has been enabled to the device."
As far as i can see there must be another port the device requires to be open, as placing the device in DMZ removes the firewall and allows this to work.
Can you check the device interface and see which ports have been set in the device as required? As there may be some obscure port set in the device which is needed.
Hope this helps
Burkem5