b. A ping command executed on PC2 to SW1 whose IP address is 192.168.21.10 gave the following results: C:\>ping 192.168.21.10 Pinging 192.168.21.10 with 32 bytes of data: Reply from 192.168.21.10: bytes=32 time=6ms TTL=126 Reply from 192.168.21.10: bytes=32 time=Sms TTL=126 Reply from 192.168.21.10: bytes=32 time=5ms TTL=126 Reply from 192.168.21.10: bytes=32 time=6ms TTL=126 Ping statistics for 192.168.21.10 Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 1ms, Average = 1ms C:\> State the purpose of the ping command and explain in detail the meaning of the results displayed above after pinging. (4 marks) c. Write two roles of switched networks. (2 marks)