46. RTP message can be duplicated since multimedia data travels in UDP. How does the receiver determine if an incoming message is a duplicate? 47. Name two steps to convert analog data to digital data. 48. What is malware? 49. What name do we give to attacks that occur before a patch is available? 50. Do firewalls usually stop viruses? 51. How do viruses and worms differ? 52. What is the purpose of denial of service attack? What is Spoofing attack? 53. What does a Firewall do if a packet probably is an attack packet? 54. What are the chief differences between IDS and Firewall? 55. What are the two modes of operation for VPN? 56. If an ISP assigned you a /23 address block, how many computers could you assign an address? 57. If an ISP offers a /25 address block for 320 dollars per month and a/28 address block for 320 dollars per month, which has the cheapest cost per computer? 58. Your IP address is 192.168.17.156 subnet mask is 255.255.255.0 What is subnet address? Broadcast address? Number of host on this network? Host address ranget