Problem #3. (5 pts) (Q13.0) Consider the following arrangement of three switches S1-S3, three hosts h1-h3 and one OpenFlow controller C. h1 h2 222 h3 53 S1 S2 S3 Please read this paragraph carefully: Assume that the switches report packets to C only if they do not have a forwarding-table entry for the packet's destination. After each report, C installs a forwarding-table entry on the reporting switch for reaching the packet's source address via the arrival port. At that point the switch floods the packet (as the destination must not have been known). If a switch can forward a packet without reporting to C, no new forwarding entries are installed. At the beginning of the transmission, switches S1, S2, and S3 have no forwarding table/flow table entry. Packets are now sent in the following steps: 1. h1-h2 2. h2-h1 3. h1-h3 4. h3-h1 5. h2h3 6. h3-h2 At the end, what are the forwarding tables on S2? (Hint: Think carefully for each step, at each switch, (1) is the destination known? (2) Will the switch report to the controller? (3) What if yes? What if no? What's the forwarding decision next? (4) If the controller installs a forwarding/flow table entry, what is it?) Answer: