How to Install Open vSwitch on Red Hat Enterprise Linux
       =======================================================

This document describes how to build and install Open vSwitch on a Red
Hat Enterprise Linux (RHEL) host.  If you want to install Open vSwitch
on a generic Linux host, see INSTALL instead.

We have tested these instructions with RHEL 5.6 and RHEL 6.0.

Building Open vSwitch for RHEL
------------------------------

You may build from an Open vSwitch distribution tarball or from an
Open vSwitch Git tree.

Before you begin, note the RPM source directory on your version of
RHEL.  On RHEL 5, the default RPM source directory is
/usr/src/redhat/SOURCES.  On RHEL 6, it is $HOME/rpmbuild/SOURCES.

1. If you are building from a distribution tarball, proceed to step 2.
   Otherwise, if you are building from an Open vSwitch Git tree,
   determine the version of Autoconf available in the RHEL version you
   are using.  If it is not at least version 2.64, then you have two
   choices:

     a. Install Autoconf 2.64 or later, one way or another.

     b. Create a distribution tarball on some other machine, by
        running "./boot.sh; ./configure; make dist" in the Git tree.
        You must run this on a machine that has the tools listed in
        INSTALL as prerequisites for building from a Git tree.
        Afterward, proceed with the rest of the instructions using the
        distribution tarball.

2. Install build prerequisites:

   yum install gcc make python-devel openssl-devel kernel-devel graphviz \
       kernel-debug-devel autoconf automake rpm-build redhat-rpm-config \
       libtool

3. Some versions of the RHEL 6 kernel-devel package contain a broken
   "build" symlink.  If you are using such a version, you must fix
   the problem before continuing.

   To find out whether you are affected, run:

       cd /lib/modules/<version>
       ls -l build/

   where <version> is the version number of the RHEL 6 kernel.  (The
   trailing slash in the final command is important.  Be sure to include
   it.)  If the "ls" command produces a directory listing, your
   kernel-devel package is OK.  If it produces a "No such file or
   directory" error, your kernel-devel package is buggy.

   If your kernel-devel package is buggy, then you can fix it with:

       cd /lib/modules/<version>
       rm build
       ln -s /usr/src/kernels/<target> build

   where <target> is the name of an existing directory under
   /usr/src/kernels, whose name should be similar to <version> but may
   contain some extra parts.  Once you have done this, verify the fix with
   the same procedure you used above to check for the problem.

4. If you are building from an Open vSwitch Git tree, then you will
   need to first create a distribution tarball by running "./boot.sh;
   ./configure; make dist" in the Git tree.

5. Copy the distribution tarball into the RPM source directory.

6. Unpack the distribution tarball into a temporary directory and "cd"
   into the root of the distribution tarball.

7. To build Open vSwitch userspace, run:

       rpmbuild -bb rhel/openvswitch.spec

   This produces two RPMs: "openvswitch" and "openvswitch-debuginfo".

   If the build fails with "configure: error: source dir
   /lib/modules/2.6.32-279.el6.x86_64/build doesn't exist" or similar,
   then the kernel-devel package is missing or buggy.  Go back to step
   1 or 2 and fix the problem.

8. On RHEL 6, to build the Open vSwitch kernel module, copy
    rhel/openvswitch-kmod.files into the RPM source directory and run:

	rpmbuild -bb rhel/openvswitch-kmod-rhel6.spec

    You might have to specify a kernel version and/or variants, e.g.:

	rpmbuild -bb \
		-D "kversion 2.6.32-131.6.1.el6.x86_64" \
		-D "kflavors default debug kdump" \
		rhel/openvswitch-kmod-rhel6.spec

    This produces an "kmod-openvswitch" RPM for each kernel variant,
    in this example: "kmod-openvswitch", "kmod-openvswitch-debug", and
    "kmod-openvswitch-kdump".

A RHEL host has default firewall rules that prevent any Open vSwitch tunnel
traffic from passing through. If a user configures Open vSwitch tunnels like
GRE, VXLAN, LISP etc., they will either have to manually add iptables firewall
rules to allow the tunnel traffic or add it through a startup script (Please
refer to the "enable-protocol" command in the ovs-ctl(8) manpage).

Red Hat Network Scripts Integration
-----------------------------------

Simple integration with Red Hat network scripts has been implemented.
Please read rhel/README.RHEL in the source tree or
/usr/share/doc/openvswitch/README.RHEL in the installed openvswitch
package for details.

Reporting Bugs
--------------

Please report problems to bugs@openvswitch.org.