Changes between Version 4 and Version 5 of GENIExperimenter/Tutorials/OpenFlowOVS/Execute

06/22/13 19:53:52 (6 years ago)



  • GENIExperimenter/Tutorials/OpenFlowOVS/Execute

    v4 v5  
    2323In order to configure our switch, we first need to login to the host that will be used as an OpenFlow switch.
    25 ===2a. Login to OVS host ===
     25=== 2a. Login to OVS host ===
    53 == 2b. Configure  the Software Switch ==
     53=== 2b. Configure  the Software Switch ===
    5454Now that you are logged in, we need first to configure OVS. To save time in the tutorial we have already started OVS and we have added an ethernet bridge that will act as our software switch. Try:
    96 === `standalone` vs `secure` mode ===
     96==== `standalone` vs `secure` mode ====
    9797The OpenFlow controller is responsible for setting up all flows on the switch, which means that when the controller is not running there should be no packet switching at all. Depending on the setup of your network, such a behavior might not be desired. It might be best that when the controller is down, the switch should default back in being a learning layer 2 switch. In other circumstances however this might be undesirable. In OVS this is a tunable parameter, called `fail-safe-mode` which can be set to the following parameters:
    9898  * `standalone` [default] : in which case OVS will take responsibility for forwarding the packets if the controller fails
    167167Can you tell now why there were packets flowing even after you killed your controller?
    169 == Useful Tips for writing your controller ==
     169=== Useful Tips for writing your controller ===
    170170In order to make this first experience of writing controller easier, we wrote some helpful functions that will abstract some of the  particularities of PoX away.
    171171These functions are locates at `/local/pox/ext/`, so while you write your controller consult this file for details.
    223223    If your controller is working you the packets registering in both terminals that you run tcpdump.
    225 == Run a port forward Controller ==
     225=== 3d. Run a port forward Controller ===
    226226Now let's do a slightly more complicated controller. OpenFlow gives you the power to overwrite fields of your packets at the switch, for example the TCP source or destination port and do port forwarding. You can have clients trying to contact a server at port 5000, and the OpenFlow switch can redirect your traffic to a service listening on port 6000.
    257257Start your controller and do the same, now your text should appear on the other terminal of host2.
    259 == Run a server proxy Controller ==
     259=== 3e. Run a server proxy Controller ===
    260260As our last exercise, instead of diverging the traffic to a different server running on the same host, we will diverge the traffic to a server running on a different host and on a different port.