代写网络作业 On line submission via Turnitin. Assignments will be marked and returned online. There are no hardcopy submissions for written assignments.
This assignment has been designed to test the following areas:
- Intra-Domain Routing
- CIDR/Route aggregation
- Inter-Domain Routing
- Answers must be within the specified word limit. This is an absolute word limit and no excess will be allowed.
- Assumptions (if any) must be stated clearly in your answers. Remember, there may not be one right answer for some of the questions. Rather, your explanations do need to present your case clearly. The explanations you provide do not have to be long, conciseness is preferred to meandering.
- For all questions in this assignment not only content but also presentation will affect your mark. You will lose marks (and not necessarily only a small portion) if there are problems with the presentation, particularly with clarity. This means that your answers to each question should be a coherent statement and that the spelling and grammar of your submission will be taken into account in assessing its presentation. For full marks, your answers should all be clear, coherent and correct. The standards of marking described in the unit outline L.O. 1-6 will be applied to this assignment as relevant to the assignment topics. In addition, the following particular standards will be applied in marking this assignment:
- Spelling and grammar: o Assignment submissions with more than 4 spelling or grammatical errors
will not achieve a grade higher than distinction; submissions with more than 8 such errors will not achieve a grade higher than credit.
o Ambiguous or poorly worded answers will receive a grade no more than a pass for the individual question.
o Minor issues of clarity will receive a grade no more than credit for the individual question.
- Correctness of approach taken and answer obtained:
o Incorrect answers with the correct logic or approach will receive no more than a pass for the individual question.
o Correct answers with incorrect logic or approach will receive no more than pass for the individual question.
o Incorrect answers with no explanation of the approach taken or with the incorrect approach will receive a fail grade for the individual question.
The questions will be marked individually, the marks totalled, and a final grade assigned that is no more than indicated by the total marks, and no more than allowed by the standards specified above and in the unit outline.
- On line submission via Turnitin. Assignments will be marked and returned online. There are no hardcopy submissions for written assignments.
Ensure you submit the correct file. The submission process shows you a complete preview of your entire assignment after you have uploaded it but before you have submitted it. Carefully check through every single page to ensure everything is there and the correct version has been uploaded, and only then press CONFIRM.
Multiple submissions may be possible via Turnitin prior to the final due date and time of an assessment task and originality reports may be made available to students to view and check their levels of similarity prior to making a final submission. Students are encouraged to use these reports to ensure that they do not breach the Academic Honesty Policy through high levels of similarity (plagiarism).
Teaching staff will use the report to judge whether plagiarism has occurred and whether penalties should apply for breaches of the Academic Honesty Policy. Any similar text identified by Turnitin will be considered carefully to see if it is indeed a breach of the Academic Honesty Policy.
1.(Intra-Domain Routing: RIP) [2 marks]
Consider the network topology shown below (figure 1-a). This network is running Routing Information Protocol (RIP) with poisoned reverse.
When the network boots up, each router’s routing table (containing the distances to each destination) initially has entries for its directly connected neighbours (refer to figure 1-b). This is router V’s initial table state. Fill in the router V’s routing table for the first five steps of the updating process (note that the process might complete before step 5).
2.(CIDR-Route Aggregation)[14 marks] 代写网络作业
a.[4 marks] Summarize the following range of IP addresses. Explain clearly how you arrive at the solution showing all relevant steps.
b.(6 marks) Consider the scenario shown in the figure (Figure 2-a) below. Arouter R1 aggregates the subnets 126.96.36.199/24 labelled [a] and 188.8.131.52/24 labelled [b] into the general prefix address 184.108.40.206/23 [ab]. Router R1 announces this general prefix [ab] to router R2 which in turn transmits it to router R3 and R4. Due to the rule of split horizon this general prefix is not readvertised back to R2 by R3 or R4 but it is exchanged between each other (R3 and R4) as shown in the figure.
At a later stage, the component prefix [b] of the general prefix [ab] is unreachable and R1 is forced to announce just the remaining single route to subnet [a] to R2 which forwards the same to R3 and R4 (refer to figure 2-b). Assume, the update message from R2 to R3 gets lost and R3 still keeps the information of the reachable general prefix [ab] received via R2 at an earlier time. Furthermore, R3 continues to exchange the general prefix [ab] with R4 which now does not have a valid route to the failed part of the general prefix. Explain in some detail what problem/s might surface if R4 accepts the general prefix [ab] from R3. (300 words)
c.(4 marks) Consider the network depicted in Figure (figure 3) below.
This campus Enterprise networks has a hierarchical architecture with a core backbone connecting all access networks. Access networks use a hub and spoke topology, whereas the core uses a ring. We assume that the routing protocol in the core has a lower administrative distance (AD) value when compared to the routing protocol running in the access network.
- Router R5 has a directly connected subnet 220.127.116.11/24, and advertises this subnetwork prefix to R2.
- Router R2 receives this route and installs it in its FIB. Since this route is a child route of 10.2.0.0/16, R2 advertises 10.2.0.0 as an aggregate route out of its interface to router R3 with a metric value of 1.
- Assume this route gets propagated in the core network and eventually comes back to router R2 via R1 with a metric value of 4.
Explain in some detail what problem/s might surface in this scenario. (250 words)
3.(Inter- Domain Routing) [3 marks] 代写网络作业
Consider the network topology shown below (Figure 4). The autonomous system AS100 has a path to the global internet via AS200, AS300 and Network Access Point (NAP). Normally you would expect AS100 to set its default to its next hop AS200 by pointing to prefix 18.104.22.168. However, in this case, AS100 has set its default to AS300 by pointing to prefix 22.214.171.124/16. What would AS100 gain by not pointing its default to a directly connected network? Since the default is not directly connected, what must be done to forward packets to it? (100 words)
4.(Inter-Domain Routing-BGP) [11 marks]
a.[5 marks] Consider the network in Figure 5, with Autonomous Systems AS1, AS2, AS3, and AS4. Each AS has some number of routers (labelled as R1, R2, etc.) and the domains are connected internally and with each other by the links depicted in the figure. Assume that eBGP and iBGP are used for inter-domain routing, and that AS1 and AS3 are using RIP for intra-domain routing while AS2 and AS4 are using OSPF for intra-domain routing. Prefix x hangs off an interface on router R11 in AS4.
i) Router R10 learns about prefix x from which routing protocol: OSPF, RIP, eBGP, or iBGP?
ii) Router R8 learns about prefix x from which routing protocol?
iii) Router R3 learns about prefix x from which routing protocol?
iv) Router R1 learns how to reach router R3 from which routing protocol?
v) Will router R1 use interface 1 or interface 2 to reach prefix X?
Consider a situation in which an Organization A is connected to the provider via two separate routers a shown in the figure below. The organization has the option of deciding which path to take for each of the routes that it accepts from the provider. The organization also has the option to influence inbound traffic. The organization deploys BGP in order to interface with its provider. Using BGP show how can the customer achieve the following objectives:
i.Outbound traffic: Traffic must be forwarded to C2 and C3 on the SF link and to C4 and C5 on the NY link.
ii.Inbound traffic: Traffic from C4 and C5 must be received by NY router on the NY link. Traffic from C2 and C3 must be received by SF router on the SF link.
iii. Default: For all the other Internet routes not known to the organization default must be taken in the primary and backup default manner. The primary default must be the NY link and the secondary default must be the SF link.