Changes between Version 21 and Version 22 of HowTo/ConfigureOVSWithLayer3Routing

08/27/14 17:29:36 (5 years ago)



  • HowTo/ConfigureOVSWithLayer3Routing

    v21 v22  
    44Open vSwitch (OVS) acts as a Layer 2 device when it's not connected to its controller (and its `fail-safe-mode` is set to standalone [default]). If we want to do Layer 3 control, we need to write the control logic in its controller. However, sometimes we want to Layer 3 control while there is other Layer 3 control. For example, we want to do firewall or NAT while there is IP routing managed by XORP or Kernel Static Routing. A straightforward solution is to write your own IP forwarding logic in your controller (Yeah, practice of writing your own XORP is fun!). This is really violating the reusability principle of software engineering. Another solution is to cross your finger and hope there is someone has written it for the controller framework you use.
     6[[Image(2boxes.png, 35%, nolink)]]
    68In this page, we are going to show you how to configure OVS to work with Linux kernel static IP routing. The method is largely from the help of Ryan Izard,, from Clemson University.
    1214The configuration we want to have is shown in below figure.
    14 [[Image(OVS Routing detail.png, 30%, nolink)]]
     16[[Image(OVS Routing detail.png, 45%, nolink)]]
    1618In summary the idea is to create a single OVS bridge for each interface on your machine that you want to assign an IP; pass the packet between the interface and the network stack through the LOCAL port of OVS; and let Linux routing handle the rest of the part.