[R2] Run a Simple Pre-Configured Experiment

New Concepts: Resource reservation, commit, ping, netstat, ifconfig, traffic plots
Review:
• xxx
Configuration File: The same configuration file used in [R1].
Description:

In this exercise, you will run traffic experiments on a network that has been configured through the RLI using the configuration file from Exercise [R1]. You must have a resource reservation to do this.

In preparation for the experiments in this section, you should know how to run the ping command with and without the -c flag, the netstat command with -i flag, and the ifconfig command. If you are unfamiliar with these command, read the man pages on these two commands on onl03.arl.wustl.edu (or any Linux host) using the commands:

	          man ping
	          man netstat
		  man ifconfig
	

Instructions:
• Log into the ONL web site, and reserve 1 cluster and 0 extra hosts for 1 hour.
• Create a tunnel to the ONL Central Resource Daemon by opening an SSH connection to onl03.arl.wustl.edu with a tunnel to port 7070.
• Start the RLI; open the cfg-route-1nsp-simple.exp configuration file; and then, get testbed resources by selecting File => Commit.
• After the resources have been successfully allocated to your experiment, answer Question 1 below. Hint: You can determine parameters values by using the left or right mouse buttons and selecting appropriate icons in the RLI.
• SSH into the host corresponding to n1p2 and run the following commands:

  	          ifconfig atm0
  	          netstat -i
  	          ping n1p3 -c 10
  	          netstat -i
  	

  Note 1: You can only SSH into onl03.arl.wustl.edu when outside of the ONL testbed. This means that you will need to SSH first into onl03 and then into your desired host.
  Note 2: You should SSH into the ethernet interface, not the ATM one; i.e., the interface will NOT be n1p2. You will be SSHing into something like onl02, onl19, onl15 or onl13. (Do you know how to determine the correct name???)
  
Answer Questions 2 and 3.
• Modify the last entry in the route table at port 2 so that its next hop is 4 (i.e., the one with a prefix/mask entry of 192.168.1.64/28). (Remember to Commit.) Enter the following command from the n1p2 host:

  	          ping n1p3
  	

  Note that this will send ping packets spaced one second apart until you kill the command by entering ctrl-c at the keyboard. Restore the next hop entry of the last entry in the route table at port 2 to 3 and commit the change. Repeat this process of toggling the next hop entry between 3 and 4 and observe the effect on the traffic chart. Answer Question 4.
• Restore the next hop field in the last entry of the route table at port 2 to its original value of 3 (i.e., the one with a prefix/mask entry of 192.168.1.64/28). (Remember to Commit.) Send a continuous stream of 1000-byte ping packets from n1p2 to n1p3. Answer Question 5.
Questions:
1. The host labeled n1p2 actually has two network interfaces: one ATM interface connected to router port 2 and one ethernet interface connected to the control network (not shown by the RLI). The label n1p2 actually refers to the ATM interface and has an IP address of 192.168.1.48. Use ifconfig atm0 to verify that the IP address assigned to the ATM interface is 192.168.1.48. What is the name of the ethernet interface?
2. The output of the netstat command should show the number of packets transmitted (TX-OK) and the number of packets received (RX-OK) for the atm0 interface. Explain why the changes in the TX-OK and RX-OK columns for the atm0 interface make sense.
3. There are six plots on your traffic graph. Explain why the plots make sense given that you just ran the ping command. Hint: Pass your mouse over each of the six labels (e.g., IPPBW 2) to highlight the corresponding line.
4. What is the effect of the Route Table changes on the traffic plots? Explain why the plots make sense.
5. What is the effect of the change in ping packet length on the traffic plots? Explain why the plots make sense.