### Information

Consider the following tree-shaped network shown below.

Initially, all the forwarding tables are empty. We are interested in the behavior of the node R4.

##### Question 1: A -> C

First, the host A sends a frame towards C. To which node(s) will R4 forward this frame?

Answer by giving the list of all such nodes, separated by a comma only. For example: R9,R6,R8.

##### Question 2: B -> C

Then, the host B sends a frame towards C. To which node(s) will R4 forward this frame?

Answer by giving the list of all such nodes, separated by a comma only. For example: R9,R6,R8.

##### Question 3: C -> A

Finally, the host C sends a frame towards A. To which node(s) will R4 forward this frame?

Answer by giving the list of all such nodes, separated by a comma only. For example: R9,R6,R8.