[ovs-discuss] Communication among different datapaths in OVS
blp at nicira.com
Thu Feb 10 12:32:09 PST 2011
On Fri, Feb 11, 2011 at 01:23:15AM +0530, Ramana Reddy wrote:
> If I am not wrong, each physical NIC associated with a separate datapath in
> This may not be true in normal linux machine, but is true in Xen or
This is a common setup but OVS does not enforce it in any way.
Yes, it is the normal setup for Xen or XenServer.
> Now I have two VMs, namely VM1 and VM2. These two are connected to
> their respective(diffrent) datapaths (or bridges) through their virtual
> interfaces(vifX.Y), and these
> two bridges are inside the OVS in the host machine.
> These are the list of Questions from my side:
> 1. How VM1 and VM2 are communicate as they belong to different datapaths.
> Is it possible in OVS.
They cannot communicate directly, because they are plugged into
different switches (bridges). This is the same as if you had two
physical machines that were plugged into different physical switches.
If the physical ports are plugged into the same Ethernet switch or
network, then they can communicate through that.
> 2. How can we visualize the OVS interms of datapaths.
Each datapath is logically equivalent to an Ethernet switch. Each
port on it is equivalent to a port on that Ethernet switch.
> 3. Each bridge ( datapath) associated with many ports, and if OVS have
> datapaths, then we can assume the OVS is a collection of bridges.
> How to communicate among these bridges inside the OVS.
If you want two VMs to communicate, then you should put their ports on
the same bridge. You can even create an additional bridge that does
not have any physical ports and put their ports on that one. (This is
equivalent to the XenServer concept of an "internal network".)
More information about the discuss