if I am using a vigor 130 on a adsl service to provide failover for a 2860 on vdsl do I need to set the 130 in bridge mode before dispatching to end user .
obviously i need to set wan to with the radius username and password and failover on the 2860 .
need to make sure the 130 is setup correctly as I will have no access remotely to this once in place .

The Vigor 130 modem is configured to pass-through PPPoE & PPPoA connections for both ADSL and VDSL out of the box - it will be able to pass through the PPPoE link / RADIUS authentication to the Vigor 2860 with no changes needed.

The Vigor 130's settings only need to be changed if passing through IPTV connections or if working directly with DHCP / Static IP connections (some ISPs like TalkTalk use this type of connection).

These KB articles

https://www.draytek.co.uk/support/guides/kb-vigor-130-bridge

https://www.draytek.co.uk/support/guides/kb-vigor-130-setup

should help