Computer Network Class questions: ( Please anwser all parts (11 - 13))
Part 3: TCP In this section, we will observe how the TCP protocol operates. We will do this by using the Minnet VM. Begin by opening wireshark and listening on the any' interface. Open a terminal window. Using wget, download the fle http://ipv4.download.thinkbroadband.com/10MB.zip 11. (15) Find the packets corresponding with the SYN, SYN-ACK, and ACK that initiated the TCP connection for this file transfer. Take a screenshot of these packets. What was the initial window size that your computer advertised to the server? What was the initial window size that the server advertised to you? 12. (10) Find a packet from the download with a source of the server and a destination of your computer. Create a teptrace graph with this packet selected. Take a screenshot of the graph and explain what it is showing. Look into the Wireshark documentation if you need assistance making this graph. In the next section, we will be simulating loss, the command tc qdisc will be needed. When you first use the command you should use add dev for the device you plan on changing. It only needs to be set on the sender's side. After adding the device use change dev Read through the following paragraph before starting the next step. Open 2 terminals and have the commands typed and ready before you begin. In one terminal, download the 10MBzip file again. While the download is in progress, change loss to 100%. After a few seconds, change loss to 0% 13. (15) Find a packet from the download with a source of the server and a destination of your computer. Create a tcptrace graph with this packet selected. Take a screenshot of the graph and explain what it is showing. Using an image editing program, circle the areas where the 0% loss is shown, as well as where TCP is in slow-start and congestion-avoidance. Part 3: TCP In this section, we will observe how the TCP protocol operates. We will do this by using the Minnet VM. Begin by opening wireshark and listening on the any' interface. Open a terminal window. Using wget, download the fle http://ipv4.download.thinkbroadband.com/10MB.zip 11. (15) Find the packets corresponding with the SYN, SYN-ACK, and ACK that initiated the TCP connection for this file transfer. Take a screenshot of these packets. What was the initial window size that your computer advertised to the server? What was the initial window size that the server advertised to you? 12. (10) Find a packet from the download with a source of the server and a destination of your computer. Create a teptrace graph with this packet selected. Take a screenshot of the graph and explain what it is showing. Look into the Wireshark documentation if you need assistance making this graph. In the next section, we will be simulating loss, the command tc qdisc will be needed. When you first use the command you should use add dev for the device you plan on changing. It only needs to be set on the sender's side. After adding the device use change dev Read through the following paragraph before starting the next step. Open 2 terminals and have the commands typed and ready before you begin. In one terminal, download the 10MBzip file again. While the download is in progress, change loss to 100%. After a few seconds, change loss to 0% 13. (15) Find a packet from the download with a source of the server and a destination of your computer. Create a tcptrace graph with this packet selected. Take a screenshot of the graph and explain what it is showing. Using an image editing program, circle the areas where the 0% loss is shown, as well as where TCP is in slow-start and congestion-avoidance
