Appendix - Move to HW switches

Notes about this tutorial

  • This is not a standalone tutorial. Please refer to the Intro to OpenFlow using OVS for background.
  • The topology used in this experiment is the same as the one used in the Intro to OpenFlow using OVS tutorial: Three virtual machines (VMs) connected by an OpenFlow switch. However this tutorial uses the hardware OpenFlow switch on the rack instead of a software OVS switch.
  • If you have not reserved a controller yet, make sure you to create a slice that will run the OpenFlow controller: Reserve a VM running the controller using the request RSpec This RSpec is available at the Portal and is called "XEN VM POX Ctrl"

About GENI OpenFlow switches
GENI offers access to hardware OpenFlow switches. Each OpenFlow switch, in most cases, can support only one controller. There are two ways of slicing the controller flowspace:

  1. By VLAN id. This is used when each slice has its own VLANs.
  2. By IP addresses or by Ethernet type. This is used when multiple slices share the same VLAN. For example, the Mesoscale VLAN 1750 that has been set up as a shared VLAN on all GENI racks.

Both approaches to slicing are covered in this tutorial.

To force the links between the VMs to go through the rack OpenFlow switch, the three VMs must be on separate physical hosts on the rack. Since each InstaGENI rack has two hosts with Xen VMs and one with OpenVZ VMs, our experiment will:

  • Use 2 Xen VMs and 1 OpenVZ VM
  • Bind the Xen VMs to different physical hosts.

1. Design/Setup

The RSpecs for this tutorial are site specific. If you are attending a tutorial, use the site and IP network that was given to you on your worksheet. If you are doing this at home, choose a site from : clemson, cornell, gatech, gpo, illinois, kansas, sky, kettering, max, missouri, northwestern, nysernet, nyu, sox, stanford, wisconsin.

1.1 Find your RSPecs

In the URLs below, replace <AGGREGATE-NAME> with the name of the site you are using (clemson, cornell, kansas, uky, kettering, max, northwestern, nysernet, stanford or wisconsin).

If you are using a private VLAN: The RSpecs you need is at:

  •<AGGREGATE-NAME>.rspec. (Reserves compute resources and specifies location of your controller.)

If you are using a shared VLAN: You will need two RSpecs, one to reserve the compute nodes and one to reserve your flowspace using the OpenFlow aggregate manager on the rack. The OpenFlow aggregate manager is called FOAM. The RSPecs are at:

  •>.rspec (Reserves compute resources.)
  •>.rspec (Reserves flowspace resources.)

1.2 Edit your RSpecs

Open your RSpec in a text editor to make the following changes:

If you are using a private VLAN:

  • Replace the string <CONTROLLER_IP> (at the bottom of the RSpec) with the IP address of your controller.

If you are using a shared VLAN:

  • In the RSpec for flowspace resources, replace:
    • SITE with the site you are using
    • NETWORK with the one in your worksheet. If you are doing this at home, use a network between 10.20.30 - 10.20.49.

1.3 Reserve Resources

If you are using a private VLAN:

  • Use your favorite resource reservation tool (Omni, jFed, Portal) to reserve your resources. For example, if you are using Omni and the MAX aggregate:

omni -a max-ig createsliver <YOUR_SLICE_NAME> ig-max.rspec

If you are using a shared VLAN:

  • You will need to reserve your compute and flowspace resources separately using your favorite resource reservation tool (Omni, jFed, Portal). For example,

omni -a max-ig createsliver <YOUR_SLICE_NAME> ig-max.rspec (to reserve compute resources)
omni -a max-ig-of createsliver <YOUR_SLICE_NAME> ig-max.rspec (to reserve flowspace resources)

Useful tips

Which port is connected to which host

Run the learning pox controller with debug on (--verbose) (use the command from the OVS tutorial) and start a ping from host1 to host2 and host3. Notice that the printout of pox will have lines like:

DEBUG:forwarding.l2_learning:installing flow for 02:b4:88:6d:83:f7.1 -> 02:36:8d:c2:b0:14.8

The format after for and -> is <MAC>.<PORT> so this way you know which port is connected to which host. To figure out the name for each port then it is simply A<PORT> so if host 1 is out of port 8, then the name is A8.

Configuration files of controllers

For the proxy and the port_forwarding controllers you will need to modify the config files (port_forward.config, proxy.config) to use the appropriate IP dataplane IP addresses of your hosts to correctly configure your controllers.


Next: Execute

Last modified 9 years ago Last modified on 02/20/15 14:06:10

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