4.3-2a Network Address Translation (a). Consider the following scenario in which host 10.0.0.1 is communicating with an external web server at IP address 128.119.40.186. The NAT table shows the table entry associated with this TCP flow. What are the source and destination IP address and port numbers at point A? S: NAT translation table WAN side addr LAN side addr 138.76.29.7, 5051 10.0.0.1, 2020 ****** S: D: 10.0.0.1

You are given with an IP address of 112.200.67.132/19. You are asked to make 6 subnets of size 60, 200, 25, 64, 4 and 12. Now, based on your calculation answer the followings: a) What is the first host IP address of subnet size 12? b) What is the broadcast address of subnet size 64? c) What is the last host IP address of the subnet size 12?

4.3-2c. Network Address Translation (c). Consider the following scenario in which host 10.0.0.1 is communicating with an external web server at IP address 128.119.40.186. The NAT table shows the table entry associated with this TCP flow. What are the source and destination IP address and port numbers at point C? OB S: B S: D: NAT translation table WAN side addr 138.76.29.7, 5051 138.76.29.7 The source IP address is: The destination IP address is: The source port number is: The destination port number is: LAN side addr 10.0.0.1, 2020 10.0.0.4 S D: S: D: [Choose ] [Choose ] 138.76.29.7 10.0.0.1 5051 10.0.0.4 80 2020 128.119.40.186 [Choose ] 10.0.0.1 10.0.0.2 10.0.0.3

An IP address can be written as a 32-bit number. For a class B network, the two most significant bits are set to 10. The 16 most significant bits are used as a network ID, and the 16 least significant bits are used as a host ID. However, the host ID cannot be all O's or all 1's. How many hosts (i.e., host IDs) can there be on a class B network? Type your answer.