Version 2 (modified by, 6 years ago) (diff)


Execute Experiment: Login to the nodes and execute a simple layer 2 experiment

Introduction: Getting Started with GENI using the GENI Portal



Now that you have reserved your resources, you are ready to run your first GENI experiment. For the purpose of this tutorial we are going to do a simple layer 2 experiment.

1. Login to nodes

Login information for a VM
  1. Return to the Slice page. Press the Details button in the row of the slice table for Utah InstaGENI.
  2. Click on the ssh link. If you have installed FireSSH a new tab will open up.
  3. In the window that will pop up :
    • in the password field type in your passphrase
    • in the private key, browse to the file that has your private key
    • Press OK
  4. If you don't have FireSSH installed, open a new terminal window. Copy the command to the right of Login into that terminal window. You have now logged into your VM.
  5. Return to the Slice page and repeat the previous two steps for GPO InstaGENI in a second terminal window.

2. Run your experiment

  1. Send IP traffic The first simple experiment that we will run is to verify the IP connectivity between our hosts.
    1. Check the interfaces of your nodes. In the terminal type:
      You should see at least two interfaces:
      • The control interface. This is the interface you use to access the node, e.g. ssh into your host. The control interface is mainly used for control traffic, i.e. traffic for controlling the node and the experiment. The control interface usually has a publicly routable IP.
      • The data interface. This is the interface that is used for sending experimental traffic. This is the interface that connects to the other hosts of your experiment through GENI. The links between these interfaces are the ones that allow you to run non-IP experiments. The data interface is the one that has an IP that starts with 10.
    2. Fill in the worksheet, noting the name and IP address of the control and of the data interfaces for each node. Note: The "client" is the node in Utah and the "server" is the node at the GPO (in Massachusetts). The command prompt on each node says "client" or "server" respectively.
    3. When we reserved the resources, we did not specify the IP address for the data interfaces. Instead, do this now. Configure the IP address on the data interface of each node using the desired data IP address from the worksheet :
          sudo /sbin/ifconfig <data i/f name> <desired data IP addr>/24
      For example:
          sudo /sbin/ifconfig mv7.90
    4. Use /sbin/ifconfig to confirm the new IP address and mask for each node. The IP address should match what you set it to and the mask should be
    5. From the client, ping the server. From the terminal window that is logged in to the client type :
          ping <server data IP addr> -c 5
      For example:
          ping -c 5
      An example output should look like :
      [sedwards@client ~]$ ping -c 5
      PING ( 56(84) bytes of data.
      64 bytes from icmp_req=1 ttl=64 time=183 ms
      64 bytes from icmp_req=2 ttl=64 time=91.2 ms
      64 bytes from icmp_req=3 ttl=64 time=91.1 ms
      64 bytes from icmp_req=4 ttl=64 time=91.1 ms
      64 bytes from icmp_req=5 ttl=64 time=91.2 ms
      --- ping statistics ---
      5 packets transmitted, 5 received, 0% packet loss, time 4004ms
      rtt min/avg/max/mdev = 91.156/109.579/183.129/36.775 ms
  1. Send non-IP traffic. GENI provides the capability of running non-IP experiments, since you can connect your hosts at Layer 2. For the purpose of this tutorial we have installed in all the hosts a very simple Layer 2 ping program that sends packets using a custom ethernet type.
    1. Disable the IP on your nodes (being careful to disable IP on the data interface NOT the control interface). In each of the terminals type:
        sudo /sbin/ifconfig <data i/f name>
      Note: Be extra careful to bring down the IP on the data interface, bringing down the IP on the control interface means that you will lose connectivity to your host.
    2. Try again to ping from the client to the server. In the terminal window of the client type:
          ping <server data IP addr> -c 5
      For example:
          ping -c 5
      This time the ping should timeout.
    3. Start the Layer 2 ping server: In the server terminal window, type:
        sudo /usr/local/bin/pingPlusListener <EtherType from worksheet>
    4. From the client try to ping the server at layer 2. You will need the mac address of the data interface of the server, the name of the data interface of the client, and the EtherType from your worksheet. In the terminal window of the client, type:
      sudo /usr/local/bin/pingPlus <server mac> <client i/f name> <Eth>
      where <server mac> is the server's data interface's MAC address, 
      <client i/f name> is the client data interface' name, and
      <Eth> is the EtherType from the worksheet.
      The result should look like :
      $ sudo /usr/local/bin/pingPlus 02:00:9B:48:3E:20 mv1.1 10001
      RQ:'5582+2067' to 2:0:9b:48:3e:20.
      RQ:5582+2067 from 2:0:3e:15:6c:ab.

3. Logout of your nodes

  • When you are done, CTRL-C in the server window to stop PingPlusListener.
  • Then type exit in each of your open terminals.

Congratulations you have run a Layer 2 experiment in GENI!

Next: Teardown Experiment