Hi im trying to configure a Draytek Vigor 2850n to use at home instead of my ISP's router which has failed. It will be connected via a single ethernet cable from the providers Optical Network Terminal to the WAN port, so this is basically just IP over Ethernet. There is a bewildering array of options on the Draytek and im by no means an expert but want i want to is

1. Set the WAN connection to be a DHCP client
2. set the VLAN (802.1q) tag to 10

Any help wold be greatly appeciated.

Who is it the ISP?

Its Eir in Ireland.

http://finbarrbrady.com/2017-07-13-replace-eir-f2000/

WAN | General | WAN 1 (or what port is your ethernet WAN port)
enable vlantag insertion and and entered the required value

WAN | Internet access | WAN 1
Static or Dynamic IP (tab)
Enable Obtain IP Address automatically.