Networking Assignment
qasmimuhammad
Assignment-1-Part3.docxNET 351 Computer Network Technologies
Written Assignment #1-Part 3 (individual)
The goal of Assignment1-Part3 is to test your understanding of the concepts related to routing in the Internet + Broadcast and multicast routing (chapters 3&4).
Note: Your answers must be typed (if not, you will get ZERO), and the late assignments policy will be applied .
Due Date: See the date on Blackboard
IMPORTANT: you must follow the instructions below. If not, you will lose marks
· Have all your answers typed
· Be clear in your answers
· Don’t copy-past content from Internet, slides, or any other source (write in your own words)
· Follow the instructions in answering the questions when given (e.g. each step in a new line)
· Include references (e.g. web site links, book chapters, course chapters, …)
Chapter 3: Review of Internet Routing Protocols (23 Marks)
I. OSPF
Figure 1: An OSPF domain topology
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b) R31 has lost the connection with R32. (6 Marks)
i. How will R31 discover that it has lost the connection? _____ _______________
ii. When will R31 send an advertisement about this? _______ ________________
iii. To whom R31 will send the advertisement (list the destinations)? Why? _______ _____________________
II. RIP, OSPF and BGP
Consider the network topology in Figure-2 below. The host H1 wants the download a file from the FTP server S2. The objective is to find the path that the request will take from the source till the destination. The routing protocols used are as specified in the figure.
Figure 2: Routing Topology
NOTE: when answering the questions below, you need to clearly explain/motivate your answer. An answer such as “because it is the shortest path” is not a complete answer, you have to explain why it is the shortest path.
a) Draw the path that the request will follow from H1 to S2? Motivate your answer (i.e. explain why it will take this route and not another one). Your response should clearly include an answer for each of the following questions:
i. Which ASs will the request go through? Why? (3 Marks)
ii. Which gateway will the request take to leave AS1? Why? (3 Marks)
iii. Draw the end to end path. You can draw the route on the same figure above using a different color. (5 Marks)
Chapter 4: Review of Broadcast and Multicast Routing (17 Marks)
III. Multicast Routing (17 Marks)
Consider the network topology in Figure-3 below.
Figure 3: Multicast/Broadcast Topology
a) Assume the metric used in the network above is number of hops. Fill the following table by providing the distance/cost from the source router to the destination subnet. (4 Marks)
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Source router |
Destination subnet |
Distance/Cost |
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R1 |
NET-1 |
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R4 |
NET-4 |
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R2 |
NET-3 |
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R1 |
NET-2 |
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b) Assume the host H1 is willing to multicast a message to the hosts H3, H4, and H5. Assume a center-based tree approach is used for multicast, R5 is selected as the center, and number-of-hops is used as metric.
i. Which routers will need to join the multicast group? (2 Marks)
ii. How will these routers know that they have to join the group? (2 Marks)
iii. Draw the multicast tree that will be used (5 Marks)
iv. Show the path the multicast message will follow, by drawing an arrow along the links that the message will use. Draw the arrows starting from H1 till all the destination hosts. (4 Marks)
A Note on Collaboration?
While students are encouraged to discuss ideas, copying another student’s answers is not allowed and a mark of zero will be assigned to all copied assignments.
What to Submit? You should type your answers in a Word document and submit that document via blackboard and also submit a print-out of the document.
H1 R31 AS1 AS2 AS3 AS4 AS5 RIP OSPF RIPv2 OSPF RIPv2 S2 R32 R35 R1 R2 R3 R4 R5 R6 R7 R8 R9 R0
RouterH4H1H3H5R1R2R3R4R5R6R7R8NET-1NET-2NET-3NET-4R9
Router H4 H1 H3 H5 R1 R2 R3 R4 R5 R6 R7 R8 NET-1 NET-2 NET-3 NET-4 R9
R31AS3OSPFArea 1Area 2Area 5R32R35Area 20Backbone areaR34R33R36R37R38R39
R31 AS3 OSPF Area 1 Area 2 Area 5 R32 R35 Area 20 Backbone area R34 R33 R36 R37 R38 R39
H1R31AS1AS2AS3AS4AS5RIPOSPFRIPv2OSPFRIPv2S2R32R35R1R2R3R4R5R6R7R8R9R0
