<info@openflowswitch.org>
-Prerequisites
--------------
+Contents
+========
+
+The OpenFlow reference implementation includes two OpenFlow switch
+implementations:
+
+ - The "kernel-based switch": This divides the switch into a
+ "datapath" Linux kernel module (openflow_mod.o for Linux 2.4
+ or openflow_mod.ko for Linux 2.6) and a userspace program
+ (secchan). The kernel-based switch is faster than either of
+ the other two implementations but requires building and
+ installing a kernel module, which can sometimes be
+ challenging.
+
+ - The "userspace datapath-based switch": This divides the
+ switch into a userspace "datapath" (built as
+ udatapath/udatapath) and the same userspace program used by
+ the kernel-based switch (secchan). The userspace
+ datapath-based switch does not require building a kernel
+ module, but it is not as fast as the kernel-based switch.
+
+The reference implementation also contains a simple OpenFlow
+controller (built as controller/controller) and a number of related
+utilities.
+
+Build Methods
+=============
-To compile the userspace programs in the OpenFlow reference
-distribution, you will need the following software:
+There are two principal ways to build and install this distribution:
+
+ - Using "configure" and "make" in the ordinary way. See
+ Building Conventionally below for detailed instructions.
+
+ - As a set of Debian packages. Refer to Building Debian
+ Packages, below, for instructions.
+
+Base Prerequisites
+------------------
+
+Regardless of how it is built, OpenFlow has a common set of
+prerequisites. To compile the userspace programs in the OpenFlow
+reference distribution, you will need the following software:
- A make program, e.g. GNU make
(http://www.gnu.org/software/make/). BSD make should also work.
- libssl, from OpenSSL (http://www.openssl.org/), is optional but
recommended. libssl is required to establish confidentiality
and authenticity in the connections among OpenFlow switches and
- controllers. To enable, compile with --enable-ssl=yes
+ controllers. To enable, configure with --enable-ssl=yes.
If you are working from a Git tree or snapshot (instead of from a
distribution tarball), or if you modify the OpenFlow build system, you
will also need the following software:
- - Autoconf version 2.59 or later (http://www.gnu.org/software/autoconf).
+ - Autoconf version 2.60 or later (http://www.gnu.org/software/autoconf).
- Automake version 1.10 or later (http://www.gnu.org/software/automake).
- pkg-config (http://pkg-config.freedesktop.org/wiki/). We test
with version 0.22.
-The optional Linux module has additional prerequisites, described
-later in the section "Building and Testing the Linux Kernel-Based
-Switch".
+Debian Prerequisites
+--------------------
+
+To build Debian packages from the OpenFlow distribution, you will need
+to install a number of Debian packages in addition to the base
+prerequisites listed above. These additional prerequisites may be
+found listed as "Build-Depends" in debian/control in the source tree.
+To check that they are installed, first install the dpkg-dev package,
+then run dpkg-checkbuilddeps from the top level of the OpenFlow source
+tree.
+
+To build Debian packages without being root, also install the
+"fakeroot" package.
+
+Kernel-Based Switch Prerequisites
+---------------------------------
+
+The OpenFlow distribution also includes a Linux kernel module that can
+be used to achieve higher switching performance. To compile the
+kernel module, you must install the following in addition to the
+software listed in the "Base Prerequisites" section above:
+
+ - A supported Linux kernel version. Please refer to README for a
+ list of supported versions.
+
+ The OpenFlow 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.
+
+ In kernels prior to 2.6.9, VLAN support (CONFIG_VLAN_8021Q) must
+ be compiled either directly or as a module. Failure to do this
+ will cause an error on module insertion due to the
+ "dev_change_flags" symbol being undefined.
+
+ - The correct version of GCC for the kernel that you are building
+ the module against:
+
+ * To build a kernel module for a Linux 2.6 kernel, you need
+ the same version of GCC that was used to build that kernel
+ (usually version 4.0 or later).
+
+ * To build a kernel module for a Linux 2.4 kernel, you need an
+ earlier version of GCC, typically GCC 2.95, 3.3, or 3.4.
+
+ - 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.
+
+Building Conventionally
+=======================
-Building Userspace Programs
----------------------------
+This section explains how to build and install the OpenFlow
+distribution in the ordinary way using "configure" and "make".
-The OpenFlow distribution includes two implementations of the switch:
-one entirely in userspace, for portability and ease of installation,
-and another with a Linux kernel module component that is more
-difficult to install but should also yield better performance. These
-instructions describe how to build the userspace components of the
-OpenFlow distribution. Refer to "Building and Testing the Linux
-Kernel-Based Switch", below, for additional instructions on how to
-build the optional Linux kernel module.
+0. Check that you have installed all the prerequisites listed above in
+ the Base Prerequisites section. If you want to compile the Linux
+ kernel module, also check that the prequisites listed under
+ Kernel-Based Switch Prequisites are installed.
1. In the top source directory, configure the package by running the
configure script. You can usually invoke configure without any
% ./configure CC=gcc-4.2
+ To build the Linux kernel module, so that you can run the
+ kernel-based switch, add --with-l26 or --with-l24 option, or both,
+ to the configure script's command line. Refer to Building the
+ Linux Kernel-Based Switch, below, for more information.
+
The configure script accepts a number of other options and honors
additional environment variables. For a full list, invoke
configure with the --help option.
The following binaries will be built:
- - Switch executable: switch/switch. This executable is built
- only if the configure script detects a supported interface to
- network devices. Refer to README for a list of OSes whose
- network device interfaces are supported.
+ - Userspace datapath: udatapath/udatapath.
- Secure channel executable: secchan/secchan.
- Runtime logging configuration utility: utilities/vlogconf.
-3. (Optional) Run "make install" to install the executables and
- manpages into the running system, by default under /usr/local.
+ - Miscellaneous utilities: utilities/ofp-discover,
+ utilities/ofp-kill.
-Testing Userspace Programs
---------------------------
+ - Tests: various binaries in tests/.
-0. The commands below must run as root, so log in as root, or use a
- program such as "su" to become root temporarily.
+ If your distribution includes the OpenFlow extensions, the
+ following additional binaries will be built:
-1. Start the OpenFlow controller running in the background, by running
- the "controller" program with a command like the following:
+ - ANSI terminal support for EZIO 16x2 LCD panel:
+ ext/ezio/ezio-term.
- # controller ptcp: &
+ - Switch monitoring UI for small text displays:
+ ext/ezio/ofp-switchui.
- This command causes the controller to bind to port 975 (the
- default) awaiting connections from OpenFlow switches. See
- controller(8) for details.
-
-2. On the same machine, use the "switch" program to start an OpenFlow
- switch, specifying network devices to use as switch ports on the -i
- option as a comma-separated list, like so:
+ If you passed --with-l26 to configure, "make" will also build the
+ following kernel modules:
- # switch tcp:127.0.0.1 -i eth1,eth2
-
- The network devices that you specify should not have configured IP
- addresses.
-
-3. The controller causes each switch that connects to it to act like a
- learning Ethernet switch. Thus, devices plugged into the specified
- network ports should now be able to send packets to each other, as
- if they were plugged into ports on a conventional Ethernet switch.
-
-Troubleshooting: if the commands above do not work, try using the -v
-or --verbose option on the controller or switch commands, which will
-cause a large amount of debug output from each program.
-
-Remote switches: These instructions assume that the controller and the
-switch are running on the same machine. This is an easy configuration
-for testing, but a more conventional setup would run a controller on
-one machine and one or more switches on different machines. To do so,
-simply specify the IP address of the controller as the first argument
-to the switch program (in place of 127.0.0.1). (Note: The userspace
-switch must be connected to the controller over a "control network"
-that is physically separate from the one that the switch and
-controller are controlling. The kernel-based switch does not have
-this limitation.)
+ - datapath/linux-2.6/openflow_mod.ko
-Secure operation over SSL
--------------------------
+ - datapath/linux-2.6/hwtable_<table>_mod.ko for each <table>
+ specified on --enable-hw-tables (if any).
-The instructions above set up OpenFlow for operation over a plaintext
-TCP connection. Production use of OpenFlow should use SSL[*] to
-ensure confidentiality and authenticity of traffic among switches and
-controllers. The source must be configured with --enable-ssl=yes to
-build with SSL support.
+ If you passed --with-l24 to configure, "make" will also build the
+ following kernel modules:
-To use SSL with OpenFlow, you must set up a public-key infrastructure
-(PKI) including a pair of certificate authorities (CAs), one for
-controllers and one for switches. If you have an established PKI,
-OpenFlow can use it directly. Otherwise, refer to "Establishing a
-Public Key Infrastructure" below.
+ - datapath/linux-2.4/openflow_mod.o
-To configure the controller to listen for SSL connections on port 976
-(the default), invoke it as follows:
+ - datapath/linux-2.6/hwtable_<table>_mod.o for each <table>
+ specified on --enable-hw-tables (if any).
- # controller -v pssl: --private-key=PRIVKEY --certificate=CERT \
- --ca-cert=CACERT
+3. Run "make install" to install the executables and manpages into the
+ running system, by default under /usr/local.
-where PRIVKEY is a file containing the controller's private key, CERT
-is a file containing the controller CA's certificate for the
-controller's public key, and CACERT is a file containing the root
-certificate for the switch CA. If, for example, your PKI was created
-with the instructions below, then the invocation would look like:
+4. If you built kernel modules, you may load them with "insmod", e.g.:
- # controller -v pssl: --private-key=ctl-privkey.pem \
- --certificate=ctl-cert.pem --ca-cert=pki/switchca/cacert.pem
+ (Linux 2.6)
+ % insmod datapath/linux-2.6/openflow_mod.ko
-To configure a switch to connect to a controller running on port 976
-(the default) on host 192.168.1.2 over SSL, invoke it as follows:
+ (Linux 2.4)
+ % insmod datapath/linux-2.4/compat24_mod.o
+ % insmod datapath/linux-2.4/openflow_mod.o
- # switch -v ssl:192.168.1.2 -i INTERFACES --private-key=PRIVKEY \
- --certificate=CERT --ca-cert=CACERT
+ After you load the openflow module, you may load one hardware switch
+ table module (if any were built) to enable support for that hardware
+ switching table.
-where INTERFACES is the command-separated list of network device
-interfaces, PRIVKEY is a file containing the switch's private key,
-CERT is a file containing the switch CA's certificate for the switch's
-public key, and CACERT is a file containing the root certificate for
-the controller CA. If, for example, your PKI was created with the
-instructions below, then the invocation would look like:
+ The insmod program must be run as root. 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 openflow_mod is
+ listed.
- # secchan -v -i INTERFACES ssl:192.168.1.2 --private-key=sc-privkey.pem \
- --certificate=sc-cert.pem --ca-cert=pki/controllerca/cacert.pem
+4. Test the userspace programs, as described under Testing Userspace
+ Programs below.
-[*] To be specific, OpenFlow uses TLS version 1.0 or later (TLSv1), as
- specified by RFC 2246, which is very similar to SSL version 3.0.
- TLSv1 was released in January 1999, so all current software and
- hardware should implement it.
+5. If you built the kernel module, test the kernel-based switch, as
+ described under Testing the Kernel-Based Implementation below.
-Establishing a Public Key Infrastructure
-----------------------------------------
+Building the Linux Kernel-Based Switch
+--------------------------------------
-If you do not have a PKI, the ofp-pki script included with OpenFlow
-can help. To create an initial PKI structure, invoke it as:
- % ofp-pki new-pki
-which will create and populate a new directory named "pki" under the
-current directory.
+To build the kernel module, follow the build process described above,
+but pass the location of the kernel build directory as an additional
+argument to the configure script, as described under step 1 in that
+section. Specify the location on --with-l26 for Linux 2.6, --with-l24
+for Linux 2.4. For example, to build for a running instance of Linux
+2.6:
-The pki directory contains two important subdirectories. The
-controllerca subdirectory contains controller certificate authority
-related files, including the following:
+ % ./configure --with-l26=/lib/modules/`uname -r`/build
- - cacert.pem: Root certificate for the controller certificate
- authority. This file must be provided to the switch or secchan
- program with the --ca-cert option to enable it to authenticate
- valid controllers.
+To build for a running instance of Linux 2.4:
- - private/cakey.pem: Private signing key for the controller
- certificate authority. This file must be kept secret. There is
- no need for switches or controllers to have a copy of it.
+ % ./configure --with-l24=/lib/modules/`uname -r`/build
-The switchca subdirectory contains switch certificate authority
-related files, analogous to those in the controllerca subdirectory:
+If you wish to build OpenFlow for an architecture other than the
+architecture used for compilation, you may specify the kernel
+architecture string using the KARCH variable when invoking the
+configure script. For example, to build OpenFlow for MIPS with Linux
+2.4:
- - cacert.pem: Root certificate for the switch certificate
- authority. This file must be provided to the controller program
- with the --ca-cert option to enable it to authenticate valid
- switches.
+ % ./configure --with-l24=/path/to/linux-2.4 KARCH=mips
- - private/cakey.pem: Private signing key for the switch
- certificate authority. This file must be kept secret. There is
- no need for switches or controllers to have a copy of it.
+If you have hardware that supports accelerated OpenFlow switching, and
+you have obtained a hardware table module for your hardware and
+extracted it into the OpenFlow reference distribution source tree,
+then you may also enable building support for the hardware switching
+table with --enable-hw-tables. For example, if your hardware
+switching table is in a directory named datapath/hwtable-foomatic, you
+could compile support for it with the running Linux 2.6 kernel like
+so:
-After you create the initial structure, you can create keys and
-certificates for switches and controllers with ofp-pki. To create a
-controller private key and certificate in files named ctl-privkey.pem
-and ctl-cert.pem, for example, you could run:
- % ofp-pki req+sign ctl controller
-ctl-privkey.pem and ctl-cert.pem would need to be copied to the
-controller for its use at runtime (they could then be deleted from
-their original locations). The --private-key and --certificate
-options of controller, respectively, would point to these files.
+ % ./configure --with-l26=/lib/modules/`uname -r`/build \
+ --enable-hw-tables=foomatic
-Analogously, to create a switch private key and certificate in files
-named sc-privkey.pem and sc-cert.pem, for example, you could run:
- % ofp-pki req+sign sc switch
-sc-privkey.pem and sc-cert.pem would need to be copied to the switch
-for its use at runtime (they could then be deleted from their original
-locations). The --private-key and --certificate options,
-respectively, of switch and secchan would point to these files.
+For more information about hardware table modules, please read
+README.hwtables at the root of the OpenFlow distribution tree.
-Building and Testing the Linux Kernel-Based Switch
---------------------------------------------------
+Building Debian Packages
+========================
-The OpenFlow distribution also includes a Linux kernel module that can
-be used to achieve higher switching performance at a cost in
-portability and ease of installation. Compiling the kernel module has
-the following prerequisites in addition to those listed in the
-"Prerequisites" section above:
+Follow these instructions to build Debian packages for OpenFlow.
- - A supported Linux kernel version. Please refer to README for a
- list of supported versions.
+0. Check that you have installed all the prerequisites listed above in
+ the Base Prerequisites and Debian Prerequisites sections above.
- The OpenFlow 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.
+1. In the top source directory, run the following command, as root:
- - The correct version of GCC for the kernel that you are building
- the module against:
+ % dpkg-buildpackage
- * To build a kernel module for a Linux 2.6 kernel, you need
- the same version of GCC that was used to build that kernel
- (usually version 4.0 or later).
+ Alternatively, if you installed the "fakeroot" package, you may run
+ dpkg-buildpackage as an ordinary user with the following syntax:
- * To build a kernel module for a Linux 2.4 kernel, you need an
- earlier version of GCC, typically GCC 2.95, 3.3, or 3.4.
+ % dpkg-buildpackage -rfakeroot
- - 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.
+ The following packages will be built in the directory above the
+ source tree:
-To build the kernel module, follow the build process described under
-"Building Userspace Programs" above, but pass the location of the
-kernel build directory as an additional argument to the configure
-script, as described under step 1 in that section. Specify the
-location on --with-l26 for Linux 2.6, --with-l24 for Linux 2.4. For
-example, to build for a running instance of Linux 2.6:
+ - openflow-controller: The OpenFlow controller. Depends on
+ openflow-pki (see below).
- % ./configure --with-l26=/lib/modules/`uname -r`/build
+ - openflow-switch: Install this package on a machine that acts
+ as an OpenFlow kernel switch.
-To build for a running instance of Linux 2.4:
+ - openflow-datapath-source: Source code for OpenFlow's Linux
+ kernel module.
- % ./configure --with-l24=/lib/modules/`uname -r`/build
+ - openflow-pki: Public-key infrastructure for OpenFlow. Install
+ this package on a machine that acts as an OpenFlow PKI server
+ (see "Establishing a Public Key Infrastructure" below).
-If you have hardware that supports accelerated OpenFlow switching, and
-you have obtained a hardware table module for your hardware and
-extracted it into the OpenFlow reference distribution source tree,
-then you may also enable building support for the hardware switching
-table with --enable-hw-tables. For example, if your hardware
-switching table is in a directory named datapath/hwtable-foomatic, you
-could compile support for it with the running Linux 2.6 kernel like
-so:
+ - openflow-common: Files and utilities required by more than one
+ of the above packages.
- % ./configure --with-l26=/lib/modules/`uname -r`/build \
- --enable-hw-tables=foomatic
+2. To set up an OpenFlow controller, install the openflow-controller
+ package and its dependencies. You may configure it by editing
+ /etc/default/openflow-controller, e.g. to enable non-SSL
+ connections, which are disabled by default. If you change the
+ default settings, you will need to restart the controller by
+ running:
-For more information about hardware table modules, please read
-README.hwtables at the root of the OpenFlow distribution tree.
+ % /etc/init.d/openflow-controller restart
-In addition to the binaries listed under step 2 in "Building Userspace
-Programs" above, "make" will build the following kernel modules:
+3. To set up an OpenFlow switch, install the openflow-switch package
+ and its dependencies. If it is to be a kernel-based switch, also
+ install openflow-datapath-source, then follow the instructions in
+ /usr/share/doc/openflow-datapath-source/README.Debian to build and
+ install the kernel module.
- datapath/linux-2.6/openflow_mod.ko (if --with-l26 was specified)
- datapath/linux-2.4/openflow_mod.o (if --with-l24 was specified)
+ You may configure the switch one of the following ways:
-"make" will also build a kernel module for each hardware switch table
-enabled with --enable-hw-tables.
+ - Completely by hand, as described under the Testing section
+ below.
-Once you have built the kernel modules, activating them requires only
-running "insmod", e.g.:
+ For the userspace datapath-based switch, this is the only
+ supported form of configuration.
- (Linux 2.6)
- % insmod datapath/linux-2.6/openflow_mod.ko
+ - By editing /etc/default/openflow-switch. You must at least
+ configure some network devices, by uncommenting NETDEVS and
+ adding the appropriate devices to the list, e.g. NETDEVS="eth0
+ eth1".
- (Linux 2.4)
- % insmod datapath/linux-2.4/compat24_mod.o
- % insmod datapath/linux-2.4/openflow_mod.o
+ After you edit this file, you will need to start the switch by
+ running:
-After you load the openflow module, you may load one hardware switch
-table module (if any were built) to enable support for that hardware
-switching table.
+ % /etc/init.d/openflow-switch restart
-The insmod program must be run as root. You may need to specify a
-full path to insmod, which is usually in the /sbin directory. To
-verify that the modules have been loaded, run "lsmod" (also in /sbin)
-and check that openflow_mod appears in the result.
+ This form of configuration is not supported for the userspace
+ datapath-based switch.
-Testing the Kernel-Based Implementation
----------------------------------------
+ - By running the ofp-switch-setup program. This interactive
+ program will walk you through all the steps of configuring an
+ OpenFlow switch, including configuration of SSL certificates.
+ Run it without arguments, as root:
-The OpenFlow kernel module must be loaded, as described in the
-previous section, before it may be tested.
+ % ofp-switch-setup
-0. The commands below must run as root, so log in as root, or use a
+ This form of configuration is not supported for the userspace
+ datapath-based switch.
+
+Testing
+=======
+
+The following sets of instructions show how to use the OpenFlow
+reference implementation as a switch on a single machine. This can be
+used to verify that the distribution built properly. For full
+installation instructions, refer to the Installation section below.
+
+Userspace Datapath
+------------------
+
+These instructions use the OpenFlow userspace datapath ("udatapath").
+
+1. Start the OpenFlow controller running in the background, by running
+ the "controller" program with a command like the following:
+
+ # controller punix:/var/run/controller.sock &
+
+ This command causes the controller to bind to the specified Unix
+ domain socket, awaiting connections from OpenFlow switches. See
+ controller(8) for details.
+
+ The "controller" program does not require any special privilege, so
+ you do not need to run it as root.
+
+2. The commands below must run as root, so log in as root, or use a
program such as "su" to become root temporarily.
-1. Create a datapath instance. The command below creates a datapath with
- ID 0 (see dpctl(8) for more detailed usage information).
+3. Create a datapath instance running in the background. The command
+ below creates a datapath that listens for connections from secchan
+ on a Unix domain socket located in /var/run and services physical
+ ports eth1 and eth2:
+
+ # udatapath punix:/var/run/dp0.sock -i eth1,eth2 &
- # dpctl adddp 0
+4. Run secchan to start the secure channel connecting the datapath and
+ the controller:
+
+ # secchan unix:/var/run/controller.sock unix:/var/run/dp0.sock &
- In principle, openflow_mod supports multiple datapaths within the
- same host, but this is rarely useful in practice.
+5. Devices plugged into the network ports specified in step 2 should
+ now be able to send packets to each other, as if they were plugged
+ into ports on a conventional Ethernet switch.
- If you built a support module for hardware accelerated OpenFlow
- switching and you want to use it, you must load it before creating
- the datapath with "dpctl adddp".
+Installation
+============
-2. Use dpctl to attach the datapath to physical interfaces on the
- machine. Say, for example, you want to create a trivial 2-port
- switch using interfaces eth1 and eth2, you would issue the following
- commands:
+This section explains how to install OpenFlow in a network with one
+controller and one or more switches, each of which runs on a separate
+machine. Before you begin, you must decide on one of two ways for
+each switch to reach the controller over the network:
- # dpctl addif 0 eth1
- # dpctl addif 0 eth2
+ - Use a "control network" that is completely separate from the
+ "data network" to be controlled ("out-of-band control"). The
+ location of the controller must be configured manually in this
+ case.
- You can verify that the interfaces were successfully added by asking
- dpctl to print the current status of datapath 0:
+ - Use the same network for control and for data ("in-band
+ control"). When in-band control is used, the location of the
+ controller may be configured manually or discovered
+ automatically. We will assume manual configuration here;
+ please refer to secchan(8) for instructions on setting up
+ controller discovery.
- # dpctl show 0
+Controller Setup
+----------------
-3. (Optional) You can manually add flows to the datapath to test using
- dpctl add-flows and view them using dpctl dump-flows. See dpctl(8)
- for more details.
+On the machine that is to be the OpenFlow controller, start the
+"controller" program listening for connections from switches on TCP
+port 6633 (the default), as shown below.
-4. The simplest way to test the datapath is to run the provided sample
- controller on the host machine to manage the datapath directly using
- netlink:
+ # controller -v ptcp:
- # controller -v nl:0
+(See controller(8) for more details)
- Once the controller is running, the datapath should operate like a
- learning Ethernet switch. You may monitor the flows in the datapath
- flow table using "dpctl dump-flows" command.
+Make sure the machine hosting the controller is reachable by the
+switch.
-The preceding instructions assume that the controller and the switch
-are running on the same machine. This is an easy configuration for
-testing, but a more conventional setup would run a controller on one
-machine and one or more switches on different machines. Use the
-following instructions to set up remote switches:
+Userspace Datapath-Based Setup
+------------------------------
-1. Start the datapath and attach it to two or more physical ports as
- described in the previous section.
+On a machine that is to host an OpenFlow userspace datapath-based
+switch, follow the procedure below.
-2. Run the controller in passive TCP mode on the host which will act as
- the controller. In the example below, the controller will bind to
- port 975 (the default) awaiting connections from secure channels.
+0. The commands below must run as root, so log in as root, or use a
+ program such as "su" to become root temporarily.
- # controller -v ptcp:
+1. Create a datapath instance running in the background. The command
+ below creates a datapath that listens for connections from secchan
+ on a Unix domain socket located in /var/run, services physical
+ ports eth1 and eth2, and creates a TAP network device named "tap0"
+ for use in in-band control:
- (See controller(8) for more details)
-
- Make sure the machine hosting the controller is reachable by the switch.
+ # udatapath punix:/var/run/dp0.sock -i eth1,eth2 --local-port=tap:tap0 &
-3. Arrange so that the switch can reach the controller over the
- network. There are two ways to do this:
+ (See udatapath(8) for details.)
- - Use a "control network" that is completely separate from the
- "data network" to be controlled. To do so, configure a
- network device (one that has not been added to the datapath
- with "dpctl addif") to access the control network in the usual
- way.
+ If the switch will connect to the controller out-of-band, then the
+ --local-port option may be omitted, or --no-local-port may be
+ substituted.
- - Use the same network for control and for data. For this
- purpose, each datapath nl:K has a corresponding virtual
- network device named ofK. Start by bringing up of0 before you
- start the secure channel:
+3. Arrange so that the switch can reach the controller over the
+ network.
- # ifconfig of0 up
+ - If you are using out-of-band control, at this point make sure
+ that the switch machine can reach the controller over the
+ network.
- Before the secure channel starts up, the of0 device cannot
- send or receive any packets, so the next step depends on
+ - If you are using in-band control with manual configuration, at
+ this point the TAP network device created in step 1 is not
+ bridged to any physical network, so the next step depends on
whether connectivity is required to configure the device's IP
address:
- . If the switch has a static IP address, you may configure
+ * If the switch has a static IP address, you may configure
+ its IP address now, e.g.:
+
+ # ifconfig tap0 192.168.1.1
+
+ * If the switch does not have a static IP address, e.g. its
+ IP address is obtained dynamically via DHCP, then proceed
+ to step 4. The DHCP client will not be able to contact
+ the DHCP server until the secure channel has started up.
+
+ - If you are using in-band control with controller discovery, no
+ configuration is required at this point. You may proceed to
+ step 4.
+
+4. Run secchan to start the secure channel connecting the datapath to
+ a remote controller. If the controller is running on host
+ 192.168.1.2 port 6633 (the default port), the secchan invocation
+ would look like this:
+
+ # secchan unix:/var/run/dp0.sock tcp:192.168.1.2
+
+ - If you are using in-band control with controller discovery, omit
+ the second argument to the secchan command.
+
+ - If you are using out-of-band control, add --out-of-band to the
+ command line.
+
+5. If you are using in-band control with manual configuration, and the
+ switch obtains its IP address dynamically, then you may now obtain
+ the switch's IP address, e.g. by invoking a DHCP client. The
+ secure channel will only be able to connect to the controller after
+ an IP address has been obtained.
+
+6. The secure channel should connect to the controller within a few
+ seconds. It may take a little longer if controller discovery is in
+ use, because the switch must then also obtain its own IP address
+ and the controller's location via DHCP.
+
+Testing the Kernel-Based Implementation
+---------------------------------------
+
+The OpenFlow kernel module must be loaded, as described under
+"Building Conventionally", before it may be used.
+
+0. The commands below must run as root, so log in as root, or use a
+ program such as "su" to become root temporarily.
+
+1. Create a datapath instance. The command below creates a datapath
+ identified as nl:0 (see dpctl(8) for more detailed usage
+ information).
+
+ # dpctl adddp nl:0
+
+ (nl:0 is the first datapath within a host. openflow_mod supports
+ multiple datapaths within the same host, which would be identified
+ as nl:1, nl:2, etc.)
+
+ Creating datapath nl:0 also creates a new network device named of0.
+ This network device, called the datapath's "local port", will be
+ bridged to the physical switch ports by the secchan, for use in
+ in-band control.
+
+ If you built a support module for hardware accelerated OpenFlow
+ switching and you want to use it, you must load it before creating
+ the datapath with "dpctl adddp".
+
+2. Use dpctl to attach the datapath to physical interfaces on the
+ machine. Say, for example, you want to create a trivial 2-port
+ switch using interfaces eth1 and eth2, you would issue the following
+ commands:
+
+ # dpctl addif nl:0 eth1
+ # dpctl addif nl:0 eth2
+
+ You can verify that the interfaces were successfully added by asking
+ dpctl to print the current status of datapath nl:0:
+
+ # dpctl show nl:0
+
+3. Arrange so that the switch can reach the controller over the
+ network.
+
+ - If you are using out-of-band control, at this point make sure
+ that the switch machine can reach the controller over the
+ network.
+
+ - If you are using in-band control, then at this point you must
+ configure the of0 network device created in step 1. This
+ device is not yet bridged to any physical network (because
+ secchan does that, and it is not yet running), so the next
+ step depends on whether connectivity is required to configure
+ the device's IP address:
+
+ * If the switch has a static IP address, you may configure
its IP address now, e.g.:
# ifconfig of0 192.168.1.1
- . If the switch does not have a static IP address, e.g. its
+ * If the switch does not have a static IP address, e.g. its
IP address is obtained dynamically via DHCP, then proceed
to step 4. The DHCP client will not be able to contact
the DHCP server until the secure channel has started up.
-4. Run secchan on the datapath host to start the secure channel
- connecting the datapath to a remote controller. (See secchan(8)
- for usage details). The channel should be configured to connect to
- the controller's IP address on the port configured in step 2.
+ - If you are using in-band control with controller discovery, no
+ configuration is required at this point. You may proceed to
+ step 4.
+
+4. Run secchan to start the secure channel connecting the datapath to
+ a remote controller. If the controller is running on host
+ 192.168.1.2 port 6633 (the default port), the secchan invocation
+ would look like this:
- If the controller is running on host 192.168.1.2 port 975 (the
- default port) and the datapath ID is 0, the secchan invocation
- would look like:
+ # secchan nl:0 tcp:192.168.1.2
- # secchan -v nl:0 tcp:192.168.1.2
+ - If you are using in-band control with controller discovery, omit
+ the second argument to the secchan command.
- If you are using separate control and data networks, or if the
- networks are combined and the switch has a static IP address, the
- secure channel should quickly connect to the controller. Setup is
- now complete. Otherwise, proceed to step 5.
+ - If you are using out-of-band control, add --out-of-band to the
+ command line.
-5. If you are using the same network for control and data, and the
+5. If you are using in-band control with manual configuration, and the
switch obtains its IP address dynamically, then you may now obtain
the switch's IP address, e.g. by invoking a DHCP client. The
secure channel will only be able to connect to the controller after
an IP address has been obtained.
+6. The secure channel should connect to the controller within a few
+ seconds. It may take a little longer if controller discovery is in
+ use, because the switch must then also obtain its own IP address
+ and the controller's location via DHCP.
+
+Configuration
+=============
+
+Secure operation over SSL
+-------------------------
+
+The instructions above set up OpenFlow for operation over a plaintext
+TCP connection. Production use of OpenFlow should use SSL[*] to
+ensure confidentiality and authenticity of traffic among switches and
+controllers. The source must be configured with --enable-ssl=yes to
+build with SSL support.
+
+To use SSL with OpenFlow, you must set up a public-key infrastructure
+(PKI) including a pair of certificate authorities (CAs), one for
+controllers and one for switches. If you have an established PKI,
+OpenFlow can use it directly. Otherwise, refer to "Establishing a
+Public Key Infrastructure" below.
+
+To configure the controller to listen for SSL connections on port 6633
+(the default), invoke it as follows:
+
+ # controller -v pssl: --private-key=PRIVKEY --certificate=CERT \
+ --ca-cert=CACERT
+
+where PRIVKEY is a file containing the controller's private key, CERT
+is a file containing the controller CA's certificate for the
+controller's public key, and CACERT is a file containing the root
+certificate for the switch CA. If, for example, your PKI was created
+with the instructions below, then the invocation would look like:
+
+ # controller -v pssl: --private-key=ctl-privkey.pem \
+ --certificate=ctl-cert.pem --ca-cert=pki/switchca/cacert.pem
+
+To configure a switch to connect to a controller running on port 6633
+(the default) on host 192.168.1.2 over SSL, invoke secchan as follows:
+
+ # secchan -v DATAPATH ssl:192.168.1.2 --private-key=PRIVKEY \
+ --certificate=CERT --ca-cert=CACERT
+
+where DATAPATH is the datapath to connect to (e.g. nl:0 or
+unix:/var/run/dp0.sock), PRIVKEY is a file containing the switch's
+private key, CERT is a file containing the switch CA's certificate for
+the switch's public key, and CACERT is a file containing the root
+certificate for the controller CA. If, for example, your PKI was
+created with the instructions below, then the invocation would look
+like:
+
+ # secchan -v DATAPATH ssl:192.168.1.2 --private-key=sc-privkey.pem \
+ --certificate=sc-cert.pem --ca-cert=pki/controllerca/cacert.pem
+
+[*] To be specific, OpenFlow uses TLS version 1.0 or later (TLSv1), as
+ specified by RFC 2246, which is very similar to SSL version 3.0.
+ TLSv1 was released in January 1999, so all current software and
+ hardware should implement it.
+
+Establishing a Public Key Infrastructure
+----------------------------------------
+
+If you do not have a PKI, the ofp-pki script included with OpenFlow
+can help. To create an initial PKI structure, invoke it as:
+ % ofp-pki init
+which will create and populate a new PKI directory. The default
+location for the PKI directory depends on how the OpenFlow tree was
+configured (to see the configured default, look for the --dir option
+description in the output of "ofp-pki --help").
+
+The pki directory contains two important subdirectories. The
+controllerca subdirectory contains controller certificate authority
+related files, including the following:
+
+ - cacert.pem: Root certificate for the controller certificate
+ authority. This file must be provided to secchan with the
+ --ca-cert option to enable it to authenticate valid controllers.
+
+ - private/cakey.pem: Private signing key for the controller
+ certificate authority. This file must be kept secret. There is
+ no need for switches or controllers to have a copy of it.
+
+The switchca subdirectory contains switch certificate authority
+related files, analogous to those in the controllerca subdirectory:
+
+ - cacert.pem: Root certificate for the switch certificate
+ authority. This file must be provided to the controller program
+ with the --ca-cert option to enable it to authenticate valid
+ switches.
+
+ - private/cakey.pem: Private signing key for the switch
+ certificate authority. This file must be kept secret. There is
+ no need for switches or controllers to have a copy of it.
+
+After you create the initial structure, you can create keys and
+certificates for switches and controllers with ofp-pki. To create a
+controller private key and certificate in files named ctl-privkey.pem
+and ctl-cert.pem, for example, you could run:
+ % ofp-pki req+sign ctl controller
+ctl-privkey.pem and ctl-cert.pem would need to be copied to the
+controller for its use at runtime (they could then be deleted from
+their original locations). The --private-key and --certificate
+options of controller, respectively, would point to these files.
+
+Analogously, to create a switch private key and certificate in files
+named sc-privkey.pem and sc-cert.pem, for example, you could run:
+ % ofp-pki req+sign sc switch
+sc-privkey.pem and sc-cert.pem would need to be copied to the switch
+for its use at runtime (they could then be deleted from their original
+locations). The --private-key and --certificate options,
+respectively, of secchan would point to these files.
+
Bug Reporting
-------------
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