QUESTION:

a) Below is a capture of an Ethernet II frame which has an IPv4 packet and a segment. Provide the source MAC address in hexadecimal; the source IP address, the length, and the header checksum of the packet in decimal; the source port number in decimal and thus deduce the application layer protocol and whether this capture relates to a response or request message.

00 13 02 4a 88 97 00 15 56 3a 4c 79 08 00 45 00
00 4c ae 91 40 00 3c 06 01 9b ca 7b 02 1a c0 a8
01 42 00 19 04 35 aa 36 09 bb e5 30 36 00 50 18
40 b0 05 fa 00 00 32 35 30 20 6f 6b 3a 20 20 4d

b) A company occupies 3 floors of a building plus the basement. Each floor is occupied by one department and adds the office of one senior manager responsible for each department. About 30 PCs having internet access are expected on each floor. The basement accommodates various server machines. For security reasons the senior managers should be accessible from the other machines only via a firewall router. The company uses a private internal network: 192.168.1.0./24. The company has an ADSL connection to the Internet. As part of this arrangement the ISP issues the company with a single public Internet address: 202.123.21.144.

Show a full network diagram for the company and make sure you identify any network devices, transmission technology and media. You have to give the IP, subnet mask and gateway addresses for all devices and servers that you find pertinent to your design. You have to also devise a scheme to allow the single public IP address to be shared among the whole staff and give special server configurations to meet company's goals. Provide the network configuration for 1 staff PC and 1 senior manager PC from each department.