Question:
Question 1 – Routing Protocols (25 marks) a) Consider the following network. With the indicated link costs, use Dijkstra’s shortest-path algorithm to compute the shortest path from x to all network nodes. Show how the algorithm works by computing a table. (10 marks)
b) Consider the three-node topology shown below. Let the link costs be c(x,y) = 3, c(y,z) = 6, c(z,x) = 4. Compute the distance tables after the initialization step and after each iteration of the distance-vector algorithm. (10 marks)
c) Consider the count-to-infinity problem in the distance vector routing. Will the count-to-infinity problem occur if we decrease the cost of a link? Why? How about if we connect two nodes which do not have a link? (5 marks)
Question 2 – IP Addressing (25 marks) a) Consider a router that interconnects three subnets: Subnet 1, Subnet 2, and Subnet 3. Suppose all of the interfaces in each of these three subnets are required to have the prefix 223.1.17/24. Also suppose that Subnet 1 is required to support up to 63 interfaces, Subnet 2 is to support up to 95 interfaces, and Subnet 3 is to support up to 16 interfaces. Provide three network addresses (of the form a.b.c.d/x) that satisfy these constraints. (10 marks) b) Consider a subnet with prefix 128.119.40.128/26. Give an example of one IP address (of form xxx.xxx.xxx.xxx) that can be assigned to this network. Suppose an ISP owns the block of addresses of the form 128.119.40.64/26. Suppose it wants to create four subnets from this block, with each block having the same number of IP addresses. What are the prefixes (of form a.b.c.d/x) for the four subnets? (10 marks) c) Write a short note on IPv6. (5 marks)
Question 3 – IP routing Configuration (50 marks)
The responsibilities of the network engineer with International Travel Agency include creating and maintaining the San Jose campus network, connectivity to all regional headquarters, and Internet access via one or more service providers. The San Jose campus network must maintain 99.9% availability, while supporting 99% availability to regional headquarters. The network will be based on and must meet the following requirements: 1. The San Jose core routers must run EIGRP. (4 marks) 2. The network has been allocated one Class B license. (2 marks) 3. Use VLSM on all serial interfaces as may be appropriate. (10 marks)
4. This network will have three branches. The regional headquarters in Singapore and Auckland will run EIGRP. The Westasman branch office will run EIGRP. The Vista and Eastasman branch offices will run IGRP. (for configuring routing protocols correctly for different locations – 10 marks)
5. Summarize all routes from each area into the core. Plan for approximately 30 networks in each area with exception of the core, which is exactly as shown in the diagram. (4 marks)
6. In the IGRP cloud of Vista and Eastasman, configure a DHCP server for a LAN segment. Use an IP helper address so that a workstation on another segment in that area can obtain an IP address from the DHCP server. (4 marks)
7. Configure Internet connectivity through a static route. (4 marks)
8. Document the configuration and any difficulties that were encountered. (4 marks)
9. What were the implementation issues or limitations? (4 marks)
10. List two suggestions for improving this network configuration and design. (4 marks)
What You Submit and How?
1. You need to submit a Report and Packet Tracer File. • Report – Should contain answers for question 1, 2 and the questions that cannot be addressed by the configuration • Packet Tracer File – You need to do the relevant configurations following the instructions and answering the questions. And you need to save the Packet Tracer configuration file.
2. Submission Instructions • Create a folder with your student ID and add both report and the Packet tracer file into the folder. • Compress the folder and create a .ZIP file (Make sure you compress you file to a zip file. If
you submit different files penalties of 5 marks will be applied.). Rename the file with your student number and name (e.g. 345678_John_Smith) • Submit the ZIP file via Moodle link. • If you do not follow above instructions 10 marks of penalties will apply.
Answer:
Answer to Question 1: Routing protocols
- Working of Dijkstra’s Shortest path algorithm
. Computation of distance tables after the initialization step and after each iteration of the distance-vector algorithm.Table: Node x Cost tox y zx 0 3 4From y ∞ ∞ ∞ z ∞ ∞ ∞ Cost tox y zx 0 3 4From y 3 0 6 z 4 6 0Table: Node y Cost tox y zx ∞ ∞ ∞From y 3 0 6 z ∞ ∞ ∞ Cost
tox y zx 0 3 4From y 3 0 6 z 4 6 0Table: Node z Cost tox y zx ∞ ∞ ∞From y ∞ ∞ ∞ z 4 6 0 Cost tox y zx 0 3 4From y 3 0 6 z 4 6 0
- The count to infinity problem would not occur in case of decreasing the cost of the link because no loops could be created by decreasing the cost of the link. If two nodes are connected that don’t have a link it would decrease the weight of the link form infinity to a finite weight.
Answer to Question 2: IP Addressing
- The calculation of the network address for the IP address 23.1.17/24.
Subnet 1: It requires 63 interfaces + 2 (broadcast + network) = thus 128 number of addresses
Subnet 2: It requires 95 interfaces + 2 (broadcast + network) = thus 128 number of addresses
Subnet 3: It requires 16 interfaces + 2 (broadcast + network) = thus 32 number of addresses
Subnet 1: 223.1.17.128/ 25 à 223.1.16.129 – 223.1.16.254
Subnet 2: 223.1.17.0 /25 à 223.1.16.1 – 223.1.16.126
Subnet 3: 223.1.18.0/ 27 à 223.1.17.1 – 223.1.17.30
- IP address within the range
128.119.40.128 – 128.119.40.191
The prefixes for the four subnets identified are given below:
- 128.119.40.64/28
- 128.119.40.80/28
- 128.119.40.112/28
-
Short note on Ipv6 – the IPv6 address is used as a replacement of the Ipv4 address for fixing the problems of limited number of IP address and addition if mire improvement such as auto configuration of the routing and the network. The length of the Ipv6 address are 128 bits and acts as an identifier for the interfaces of the network device. A multiple IPV6 address can be assigned to a single interface such as unicast address, anycast address and multicast address.
Answer to Question 3: IP Routing and Configuration
- Configuration of the Core Router with EIGRP
SanJones 1
SanJones 2
SanJones 3
- Allocation of one Class B IP address
- Use of VLSM on all serial Interface
|
Step
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N’
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D(t),p(t)
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D(u),p(u)
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D(v),p(v)
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D(w),p(w)
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D(y),p(y)
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D(z),p(z)
|
|
0
|
X
|
∞
|
∞
|
3, x
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6, x
|
5, x
|
7, x
|
|
1
|
Xv
|
6, v
|
6, x
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3, x
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6, x
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5, x
|
7, x
|
|
2
|
Xvu
|
6, v
|
6, x
|
3, x
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6, x
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5, x
|
7, x
|
|
3
|
Xvuw
|
6, v
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6, x
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3, x
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6, x
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5, x
|
7, x
|
|
4
|
Xvuwy
|
6, v
|
6, x
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3, x
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6, x
|
5, x
|
7, x
|
|
5
|
Xvuwyt
|
6, v
|
6, x
|
3, x
|
6, x
|
5, x
|
7, x
|
|
6
|
Xvuwytz
|
6, v
|
6, x
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3, x
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6, x
|
5, x
|
7, x
|
. Network Plan
- Configuration of DHCP server in Vista and Eastasman
- Configuration of Internet Connectivity using a Static route
- Documentation of the configurations
The main problem was faced during configuration of the interface with the IP address and maintaining 99.9 percent availability of the IP address in the network.
- Implementation Issues and limitations
For the implementation of the network the scalability and performance of the network should be evaluated and the data packets should transverse to all the needs of the network. During the testing of the network the data transfer of data may be sometimes unsuccessful due to designing the network in the simulation software.
- Two suggestions for the improvement of the configuration and design
The two suggestion for the improvement of the design are given below:
- Increasing the security of the network with the implementation of a network firewall between the entry and the exit point of the network, and
- Implementation of wireless router for enabling the users of the network to connect their wireless devices with the network.
|
Number of host addresses required
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Number of host address required
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Subnet network address
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Subnet mask
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Subnet/ Value
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Max number of hosts possible
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Future Use
Y/N
|
VLAN
Name
|
|
1
|
SanJose 1
|
192.168.5.225
|
255.255.255.252
|
/30
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2
|
Y
|
SanJose 1
|
|
1
|
|
192.168.5.234
|
255.255.255.252
|
/30
|
2
|
Y
|
SanJose 1
|
|
60
|
|
192.168.5.129
|
255.255.255.192
|
/26
|
62
|
Y
|
SanJose 1
|
|
1
|
|
192.168.0.193
|
255.255.255.192
|
/30
|
2
|
Y
|
SanJose 1
|
|
1
|
SanJose 2
|
192.168.5.230
|
255.255.255.252
|
/30
|
2
|
N
|
SanJose 2
|
|
1
|
|
192.168.5.233
|
255.255.255.252
|
/30
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2
|
N
|
SanJose 2
|
|
30
|
|
192.168.5.193
|
255.255.255.224
|
/27
|
30
|
N
|
SanJose 2
|
|
2
|
SanJose 3
|
192.168.5.226
|
255.255.255.252
|
/30
|
2
|
N
|
SanJose 3
|
|
2
|
|
192.168.5.229
|
255.255.255.252
|
/30
|
2
|
N
|
SanJose 3
|
|
126
|
|
192.168.5.1
|
255.255.255.128
|
/25
|
126
|
N
|
SanJose 3
|
|
2
|
Singapore
|
192.168.5.237
|
255.255.255.252
|
/30
|
2
|
N
|
Singapore
|
|
254
|
|
192.168.20.1
|
255.255.255.0
|
/24
|
254
|
Y
|
Singapore
|
|
2
|
Auckland
|
192.168.20.2
|
255.255.255.0
|
/24
|
254
|
Y
|
Auckland
|
|
30
|
Westasman
|
192.168.5.130
|
255.255.255.224
|
/27
|
30
|
Y
|
Westasman
|
|
2
|
Vista
|
192.168.5.194
|
255.255.255.252
|
/30
|
2
|
N
|
Vista
|
|
254
|
|
192.168.10.1
|
255.255.255.0
|
/24
|
254
|
Y
|
Vista
|
|
254
|
Eastasman
|
192.168.10.2
|
255.255.255.0
|
/24
|
254
|
Y
|
Eastasman
|
|
|
Internet
|
172.16.0.1
|
255.255.255.240
|
/28
|
14
|
Y
|
Internet
|
Bibliography
Goralski, W., 2017. The Illustrated network: How TCP/IP works in a modern network. Morgan Kaufmann.
Horn, A., Ostwald, D., Reisert, M. and Blankenburg, F., 2014. The structural–functional connectome and the default mode network of the human brain. Neuroimage, 102, pp.142-151.
Hung, P.C., Kamen, K., Yasuto, S., Katsuhiko, Y., Masakatsu, N., Hiroshi, M. and Valerie, W., 2015, September. Towards advanced networking and m-services with enhanced information security and integrated support for big data analytics. In JJAP Conference Proceedings (Vol. 4). The Japan Society of Applied Physics.
Kuang, D., Yan, Q., Nie, Y., Feng, S. and Li, J., 2015, December. Image seam line method based on the combination of dijkstra algorithm and morphology. In Sixth International Conference on Electronics and Information Engineering (Vol. 9794, p. 97941R). International Society for Optics and Photonics.
Support, P., Products, E., Mainline, C. and References, C. (2018). [online] Cisco. [Accessed 21 Jan. 2018].
Swathika, O.G. and Hemamalini, S., 2016. Prims-Aided Dijkstra Algorithm for Adaptive Protection in Microgrids. IEEE Journal of Emerging and Selected Topics in Power Electronics, 4(4), pp.1279-1286.
