OSPF Path Selection Lab

Hi,

I just completed the OSPF Path Selection and achieved its objectives but the placement of costs to achieve the results in the solution is different to my choices.

I set the cost on R3’s tunnel interface to 2 so that R3 and R6 would inject summary LSAs into Area 2 with the same metric, thus giving R7 two equal cost paths to reach Host10.

The solution, however, sets R3’s tunnel interface cost to 1 and then increases R7’s link cost to R3 to 2. So although the summary LSA’s are being injected with different metrics, R7 will still see two equal cost paths to Host10.

My question is, why was it done this way?