I'm fairly new to the superb Draytek 2860. I've set a few up fixed IP address for ADSL, configured LANs and restricted ports for incoming traffic redirected to a specific Server.

However, I now need ADD a (completely independent) sister network which needs a different fixed IP address from the ISP's range
e.g. if 80.100.100.50 was main Server's address - the new network (needs to be completely separate) can be on 80.100.100.52
I'm assuming it may be to do with VLAN or would it be IP ROUTER SUBNET - not sure where to start. Does it matter which one of the 6x Ports I connect it to and where do I tell the router to allocate that one.
I'm assuming it's not to be connected to WAN2 as that should be for incoming - like a 2nd ISP.

Can someone point me in the correct direction...thanks!

You need to set up the IP routed subnet
https://www.draytek.com/en/faq/faq-connectivity/connectivity.lan/how-to-use-a-public-ip-on-lan/

Thanks. I found that article and have tried that.
After several hours messing around I can get internet access on the VLAN part but the IP Address resolves to be the same as the Primary LAN one! despite being set to different IP. I'm not sure where to go next!