openvswitch/INSTALL.Linux

                 How to Install Open vSwitch on Linux
                 ====================================

This document describes how to build and install Open vSwitch on a
generic Linux host.  If you want to install Open vSwitch on a Citrix
XenServer version 5.5.0, see INSTALL.XenServer instead.

This version of Open vSwitch should be built manually with "configure"
and "make".  Debian packaging for Open vSwitch is also included, but
they have not been recently tested, and so Debian packages are not a
recommended way to use this version of Open vSwitch.

Build Requirements
------------------

To compile the userspace programs in the Open vSwitch distribution,
you will need the following software:

    - A make program, e.g. GNU make.  BSD make should also work.

    - The GNU C compiler.  We generally test with version 4.1, 4.2, or
      4.3.

    - libssl, from OpenSSL, is optional but recommended if you plan to
      connect the Open vSwitch to an OpenFlow controller.  libssl is
      required to establish confidentiality and authenticity in the
      connections from an Open vSwitch to an OpenFlow controller.  To
      enable, configure with --enable-ssl=yes.

To compile the kernel module, you must also install the following.  If
you cannot build or install the kernel module, you may use the
userspace-only implementation, at a cost in performance.  The
userspace implementation may also lack some features.  Refer to
INSTALL.userspace for more information.

    - A supported Linux kernel version.  Please refer to README for a
      list of supported versions.

      The Open vSwitch datapath requires bridging support
      (CONFIG_BRIDGE) to be built as a kernel module.  (This is common
      in kernels provided by Linux distributions.)  The bridge module
      must not be loaded or in use.  If the bridge module is running
      (check with "lsmod | grep bridge"), you must remove it ("rmmod
      bridge") before starting the datapath.

      For optional support of ingress policing, you must enable kernel
      configuration options NET_CLS_ACT, NET_CLS_U32, NET_SCH_INGRESS,
      and NET_ACT_POLICE, either built-in or as modules.
      (NET_CLS_POLICE is obsolete and not needed.)

      If GRE tunneling is being used it is recommended that the kernel
      be compiled with IPv6 support (CONFIG_IPV6).  This allows for
      special handling (such as path MTU discovery) of IPv6 packets.

    - To build a kernel module, you need the same version of GCC that
      was used to build that kernel.

    - A kernel build directory corresponding to the Linux kernel image
      the module is to run on.  Under Debian and Ubuntu, for example,
      each linux-image package containing a kernel binary has a
      corresponding linux-headers package with the required build
      infrastructure.

If you are working from a Git tree or snapshot (instead of from a
distribution tarball), or if you modify the Open vSwitch build system,
you will also need the following software:

    - Autoconf version 2.64 or later.

    - Automake version 1.10 or later.

    - pkg-config.  We test with version 0.22.

    - Python 2.x, for x >= 4.

If you modify the ovsdbmonitor tool, then you will also need the
following:

    - pyuic4 from PyQt4 (http://www.riverbankcomputing.co.uk).

Installation Requirements
-------------------------

The machine on which Open vSwitch is to be installed must have the
following software:

    - libc compatible with the libc used for build.

    - libssl compatible with the libssl used for build, if OpenSSL was
      used for the build.

    - The Linux kernel version configured as part of the build.

    - For optional support of ingress policing, the "tc" program from
      iproute2 (part of all major distributions and available at
      http://www.linux-foundation.org/en/Net:Iproute2).

    - For debugging purposes, Open vSwitch expects that "tcpdump" is
      installed as /usr/sbin/tcpdump.  If tcpdump is not installed, or
      if it is installed in a different location, then some Open
      vSwitch log messages will not be as detailed.

To run the ovsdmonitor tool, the machine must also have the following
software:

    - Python 2.x, for x >= 4.

    - Python Twisted Conch.

    - Python JSON.

    - PySide or PyQt4.

    - Python Zope interface module.

(On Debian "lenny" the above can be installed with "apt-get install
python-json python-qt4 python-zopeinterface python-twisted-conch".)

Building and Installing Open vSwitch for Linux
==============================================

Once you have installed all the prerequisites listed above in the Base
Prerequisites section, follow the procedure below to build.

1. If you pulled the sources directly from an Open vSwitch Git tree, 
   run boot.sh in the top source directory:

      % ./boot.sh

2. In the top source directory, configure the package by running the
   configure script.  You can usually invoke configure without any
   arguments:

      % ./configure

   By default all files are installed under /usr/local.  If you want
   to install into, e.g., /usr and /var instead of /usr/local and
   /usr/local/var, add options as shown here:

      % ./configure --prefix=/usr --localstatedir=/var

   To use a specific C compiler for compiling Open vSwitch user
   programs, also specify it on the configure command line, like so:

      % ./configure CC=gcc-4.2

   To build the Linux kernel module, so that you can run the
   kernel-based switch, pass the location of the kernel build
   directory on --with-l26.  For example, to build for a running
   instance of Linux 2.6:

      % ./configure --with-l26=/lib/modules/`uname -r`/build

   If you wish to build the kernel module for an architecture other
   than the architecture of the machine used for the build, you may
   specify the kernel architecture string using the KARCH variable
   when invoking the configure script.  For example, to build for MIPS
   with Linux 2.6:

      % ./configure --with-l26=/path/to/linux-2.6 KARCH=mips

   The configure script accepts a number of other options and honors
   additional environment variables.  For a full list, invoke
   configure with the --help option.

3. Run make in the top source directory: 

      % make

4. Become root by running "su" or another program.

5. Run "make install" to install the executables and manpages into the
   running system, by default under /usr/local.

6. If you built kernel modules, you may load them with "insmod", e.g.:

      % insmod datapath/linux-2.6/openvswitch_mod.ko

   You may need to specify a full path to insmod, e.g. /sbin/insmod.
   To verify that the modules have been loaded, run "/sbin/lsmod" and
   check that openvswitch_mod is listed.

7. Initialize the configuration database using ovsdb-tool, e.g.:

      % ovsdb-tool create /usr/local/etc/ovs-vswitchd.conf.db vswitchd/vswitch.ovsschema

Startup
=======

Before starting ovs-vswitchd itself, you need to start its
configuration database, ovsdb-server.  Configure it to use the
database you created during step 7 of installation, above, and to
listen on a Unix domain socket, e.g.:

      % ovsdb-server /usr/local/etc/ovs-vswitchd.conf.db --remote=punix:/usr/local/var/run/openvswitch/db.sock

Then initialize the database with "ovs-vsctl init".  This is only
necessary the first time after you create the database with
ovsdb-tool (but running it at any time is harmless):

      % ovs-vsctl init

Then start the main Open vSwitch daemon, telling it to connect to the
same Unix domain socket:

      % ovs-vswitchd unix:/usr/local/var/run/openvswitch/db.sock

Now you may use ovs-vsctl to set up bridges and other Open vSwitch
features.  For example, to create a bridge named br0 and add ports
eth0 and vif1.0 to it:

      % ovs-vsctl add-br br0
      % ovs-vsctl add-port br0 eth0
      % ovs-vsctl add-port br0 vif1.0

Please refer to ovs-vsctl(8) for more details.

Bug Reporting
-------------

Please report problems to bugs@openvswitch.org.