The answer to question 01: VLANs use to isolate broadcast domains. The answer to question 02: Range of class D 224.0.0.0-239.255.255.255. Class D IP addresses are used for multi-casting. The answer to question 03: 195.243.67.51 11001101 01110100 00000100 00101110 11001111 10000001 01111110 10010010 213.54.53.52