ECMP Spillover with redundant Tunnels

[Jan_Scholten]

I am using redundant Tunnels towards other Destinations (e.g. 4 Tunnels from Hub -> Spoke ) I run OSPF over this Tunnels, so i get 4 routes with same chracteristics. 

ECMP seems to work, i get Sessions on all Tunnel-Interfaces.

Now i tried to favor one of the tunnels (as this orginiates from the biggest connection).

I tried with ECMP Spillover setting a high value on the Tunnel-interface.

-> cleared all Sessions, new sessions a distributed across all tunnels, even more are on a Tunnel with no threshold

I would expect that traffic will use only the Interface with the high threshold.

I also tried with weight (giving the preffered tunnel a high weight, the others a significant lower weight)

Same results no preference of the tunnel is seen.

Am i missing something? e.g. is it not working on routes received by OSPF via Tunnel interfaces? 

Any hints?