[ovs-discuss] How to configure VxLAN tunnel with OpenVSwitch-2.7.0 on Ubuntu14.04.1 ?
scott.lowe at scottlowe.org
Mon Jul 17 03:14:09 UTC 2017
> On Jul 16, 2017, at 9:30 AM, sujz <drizzle_su at 126.com> wrote:
> Hi, ALL:
> I want to connect VMs located on two different machines with ovs bridge and VxLAN tunnel, suppose the topology as the picture <topo.png>
> shows, my configuration on host A like this(configuration on host B is almost the same except changing remote_ip to address of host A'eth0):
> ovs-vsctl add-br ovs-br0
> ovs-vsctl add-port ovs-br0 vtep -- set interface vtep type=vxlan options:remote_ip=188.8.131.52 options:key=5000
> tap0 is created and automatically added to bridge ovs-br0 while starting VMs with qemu, but I cannot ping from VM1 to VM2.
> I also googled some links like this: http://networkstatic.net/configuring-vxlan-and-gre-tunnels-on-openvswitch/ , which says I have to create two ovs-bridge, unfortunately, it doesn't tell whether(and how to) it is necessary to link these two bridges together.
> I am confused that how does the ovs-br0 and eth0 communicate, does that the kernel TCP/IP stack help doing this job, or I have to create another ovs-bridge and connect these two bridges with patch ports ?
> So please correct me if my topology or configurations aren't right, and many thanks in advance.
> I also tried to configure vtep: ovs-vsctl add-port ovs-br0 vtep -- set interface vtep type=vxlan options:remote_ip=flow options:local_ip=flow options:key=flow Then add flow entry explicitly to match ARP request from VM1 and forward them to vtep. ovs-ofctl add-flow ovs-br0 "table=0, priority=50, in_port=ofport_of_tap0, actions=output:ofport_of_vtep". After ping from VM1 to VM2, dump-flows showed that the added entry was matched (according to the entry matched packets should be forwarded to vtep), but dump-ports showed that vtep received nothing, I don't know why, any hints are appreciated.
If I’m understanding your configuration correctly, you don’t need an additional bridge. The OVS bridge hosting the VTEP (and the TAP interface) doesn’t need any additional interfaces or patch ports; you just need to ensure that the host system has a route to the tunnel endpoint on the other host. You may also need to adjust the MTU, since the VXLAN encapsulation adds some overhead.
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