CS代考 COMP90007 Internet Technologies Week 8 Workshop – cscodehelp代写
COMP90007 Internet Technologies Week 8 Workshop
Semester 2, 2021
* © University of Melbourne 2021 1
A router has just received the following IP addresses: 220.127.116.11/21, 18.104.22.168/21, 22.214.171.124/21 and 126.96.36.199/21. If all of them use the same outgoing line, can they be aggregated? If so, to what? If not, why not?
They can be aggregated to 188.8.131.52/19
Why do we need routing algorithms in the Network layer? What are the key categories of routing algorithms?
Answer: Routing algos are needed to help decide on which output line an incoming packet should be transmitted.
Key Categories: 📫Non-Adaptive Algorithms 📫Adaptive Algorithms
Compute the sink tree for Node F in the graph below:
Ans. Refer to Dijkstra’s algorithm on the Slides 53-55 of Network Layer
Distance vector routing is used for the diagram shown below, and the following vectors have just come in to router C: from B: (5, 0, 8,
12, 6, 2); from D: (16, 12, 6, 0, 9, 10); and from E: (7, 6, 3, 9, 0, 4). The cost of the links from C to B, D, and E, are 6, 3, and 5, respectively. What is C’s new routing table? Give both the outgoing line to use and the expected delay.
Answer: Using the delays 6, 3, and 5 for B, D, and E, the vectors will be written as:
If the Path MTU Discovery is used to send a packet of 1200 bytes from the source to the destination as shown in Figure. The maximum packet size for each network on the path is labelled on the link.
■ How many trials does the source machine need to send this packet?
■ Which routers on the path send ICMP messages to the source?
800 1100 600 800
Answer: (1) The packet can be delivered after 2 trials
(2) routers A, and C will send ICMP messages “Destination Unreachable” to the source. The initial message is 1200 bytes, and router A will send ICMP message.
After processing, the packet will be 800 bytes, and router C
will send ICMP message, as the MTU of the following network
is 600 bytes. After this trial, the packet can be sent to the