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==========================================
Native Tunneling in Open vSwitch Userspace
==========================================

Open vSwitch supports tunneling in userspace. Tunneling is implemented in
a platform-independent way.

Setup
-----

Setup physical bridges for all physical interfaces. Create integration bridge.
Add VXLAN port to int-bridge. Assign IP address to physical bridge where
VXLAN traffic is expected.

Example
-------

Connect to VXLAN tunnel endpoint logical IP: ``192.168.1.2`` and
``192.168.1.1``.

Configure OVS bridges as follows.

1. Let's assume ``172.168.1.2/24`` network is reachable via ``eth1``. Create
   physical bridge ``br-eth1``. Assign IP address (``172.168.1.1/24``) to
   ``br-eth1``. Add ``eth1`` to ``br-eth1``.

2. Check ovs cached routes using appctl command.

   ::

       $ ovs-appctl ovs/route/show

   Add tunnel route if not present in OVS route table.

   ::

       $ ovs-appctl ovs/route/add 172.168.1.1/24 br-eth1

3. Add integration bridge ``int-br`` and add tunnel port using standard syntax.

   ::

       $ ovs-vsctl add-port int-br vxlan0 \
         -- set interface vxlan0 type=vxlan options:remote_ip=172.168.1.2

4. Assign IP address to ``int-br``.

The final topology should looks like so:

::

    Diagram

     192.168.1.1/24
    +--------------+
    |    int-br    |                                    192.168.1.2/24
    +--------------+                                   +--------------+
    |    vxlan0    |                                   |    vxlan0    |
    +--------------+                                   +--------------+
           |                                                  |
           |                                                  |
           |                                                  |
     172.168.1.1/24                                           |
    +--------------+                                          |
    |    br-eth1   |                                   172.168.1.2/24
    +--------------+                                  +---------------+
    |    eth1      |----------------------------------|      eth1     |
    +--------------+                                  +---------------+

    Host A with OVS.                                      Remote host.

With this setup, ping to VXLAN target device (``192.168.1.2``) should work.

Tunneling-related Commands
--------------------------

Tunnel routing table
~~~~~~~~~~~~~~~~~~~~

To add route:

::

    $ ovs-appctl ovs/route/add <IP address>/<prefix length> <output-bridge-name> <gw>

To see all routes configured:

::

    $ ovs-appctl ovs/route/show

To delete route:

::

    $ ovs-appctl ovs/route/del <IP address>/<prefix length>

To look up and display the route for a destination:

::

    $ ovs-appctl ovs/route/lookup <IP address>

ARP
~~~

To see arp cache content:

::

    $ ovs-appctl tnl/arp/show

To flush arp cache:

::

    $ ovs-appctl tnl/arp/flush

Ports
~~~~~

To check tunnel ports listening in ovs-vswitchd:

::

    $ ovs-appctl tnl/ports/show

To set range for VxLan UDP source port:

::

    $ ovs-appctl tnl/egress_port_range <num1> <num2>

To show current range:

::

    $ ovs-appctl tnl/egress_port_range

Datapath
~~~~~~~~

To check datapath ports:

::

    $ ovs-appctl dpif/show

To check datapath flows:

::

    $ ovs-appctl dpif/dump-flows