1. Problems with short answers [6 questions, total = 40 marks]
1. Table 1(a) shows the routing table of a particular edge router. If the rules of “no IP network
address (host bits are all zeros)” and “no IP broadcast address (host bits are all ones)” are
applied in ALL cases, answer the following questions: [Total = 10 marks]
(i) What is the gateway IP address attached to FastEthernet0/1 (Note: last usable IP
address)? (2 marks)
(ii) What is/are the likely public IP address(es) for this edge router? (5 marks)
Edge_Router#show ip route
...
Gateway of last resort is 202.50.111.205 to network 0.0.0.0
172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
C 172.16.180.64/26 is directly connected, FastEthernet0/0
C 172.16.180.128/26 is directly connected, FastEthernet0/1
C 172.16.181.128/25 is directly connected, FastEthernet1/0
202.50.111.0/29 is subnetted, 1 subnets
C 202.50.111.200/29 is directly connected, FastEthernet1/1
S* 0.0.0.0/0 [1/0] via 202.50.111.205
Table 1(a)
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Answer:

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2. Figure 2(a) shows the IP addresses and MAC addresses of the PC, routers, and server. Figure
2(b) shows that PC0 is accessing the web service of Server0 (assume that the client port
number = 1028). Fill in the blanks of the both part (a) and part (b), with the correct addresses.
[Total = 12 marks]
Figure 2(a)
Figure 2(b)
a) PC0 send http request to Server0. Data is now on Cable 2: (1 mark for each blank)
Source Port:________________ Destination Port:________________
Source IP:_________________ Destination IP:__________________
Source MAC:______________ Destination MAC:________________

3. b) Server0 returns http data to PC0. Data is now on Cable 3: (1 mark for each blank)
Source Port:________________ Destination Port:________________
Source IP:_________________ Destination IP:__________________
Source MAC:______________ Destination MAC:________________
3. Based on Figure 3, list the range of subnet mask(s) that is/are applicable in this network in
which all PCs will be able to communicate with each other. The IP addresses of the PCs are
unspecified and can be any usable host IP of the subnet. (Note: The same subnet mask is
configured in PCs and Router0. For example, if I choose the subnet mask to be /12, then it
will be configured in all the PCs and Router0). [Total = 5 marks]
Figure 3
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Answer:
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4. 4. I have obtained the IP addresses of a few public DNS server (e.g: 202.188.0.133;
202.188.1.5; 202.188.1.23; 202.75.44.18; 213.196.2.97; 202.188.0.181). I want use two of
them to be my ‘Preferred DNS server”, and “Alternate DNS server” since I want to have my
PC to be configured in static IP. List three network commands that will help me to make a
wise decision to select the DNS IP. Assume that my PC hasn’t got any dynamic IP.
(Note: your answer is just two command names. For example: ipconfig, ftp, telnet, etc).
[Total = 3 marks]
Figure 4
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Answer:
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5. Table 5 shows the routing table of Router1. List all the essential commands to be entered in
Router1 in order to form this routing table and to help the dynamic routing in the network.
Please write your answer in the following format: Router1(config)#int fa0/0, a prompt
followed by the command. Assume the Router1 IP addresses to be the first usable IP of the
subnet. . [Total = 10 marks]

5. Router1#show ip route
……
Gateway of last resort is not set
R 10.0.0.0/8 [120/1] via 150.0.1.2, 00:00:14, FastEthernet0/1
[120/1] via 200.0.1.2, 00:00:09, Serial0/0
[120/1] via 200.0.4.2, 00:00:05, Serial0/1
150.0.0.0/24 is subnetted, 2 subnets
C 150.0.1.0 is directly connected, FastEthernet0/1
R 150.0.2.0 [120/1] via 150.0.1.2, 00:00:14, FastEthernet0/1
R 172.16.0.0/16 [120/2] via 200.0.4.2, 00:00:05, Serial0/1
C 192.168.1.0/24 is directly connected, FastEthernet0/0
C 200.0.1.0/24 is directly connected, Serial0/0
R 200.0.2.0/24 [120/1] via 200.0.1.2, 00:00:09, Serial0/0
R 200.0.3.0/24 [120/2] via 200.0.4.2, 00:00:05, Serial0/1
C 200.0.4.0/24 is directly connected, Serial0/1
Router1#
Table 5
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Answer:

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6. Based on the following output of the nmap command, list the GUI client softwares that you
can have communication with 202.1.1.230. [Total = 3 marks]
c:>nmap –vv –PS 202.1.1.230
....(output)
PORT STATE
22/tcp open
53/tcp open
8080/tcp open
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Answer:
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(Note: Total marks = 110, but capped at 100.)