(c) The topology of an Ethernet LAN is indicated in the Figure 1. It consists of 3 hosts A (11:22:AA), B (33:44:BB) and C (55:66:CC) connected to Switches S1, S3 and S2 respectively. The last three octets of the host MAC addresses are indicated in brackets. The switch ports used are indicated in the Figure 1. Switches S1 and S2 are connected using ports Fa0/12. Switches S2 and 53 are connected using ports Fa0/23. The switch MAC address tables are initially empty. Assume A sends a message to C, B sends a message to A and A sends a message to B. Neither of these messages require a reply. Outline two functions of the OSI reference model layer at which switches operate. Indicate the content of the Switch S2 MAC address table after each frame have been sent. Justify your answer. [7.3 marks] Figure 1 Fa0/1 Fa0/1 A S1 S3 B S2 Fa0/1