Three routers, as WAN/Back-up?

[Turbo20VT]

Hello,

I have now one Draytek Vigor 2925 router, with 7 Access Points. Three modems, are connected now with the Draytek Vigor 2925 Router. (It's now connected also with three hubs)

I wanna connect now, another Vigor 2925 and 2920 Router, for back-up/and better Internet flow.
So I tried put the three routers in, and each WAN (modum UTP cable), to connect with the 2nd en 3rd router, but I don't see any WAN IP? In the Vigor 2925, and 2920.

How should I do this?
Thanks all!

 

[kanewolf]

You need a triple WAN input router. The TL-R470T supports three WAN inputs. Even with a multi-WAN router, a single transaction from a single client will only use ONE of the three paths.

 

[Turbo20VT]

The Vigor 2920 isn't and Multi-wan router? three routers, have both 2 WAN ports.
Is er any other solution possible? Thanks