supplanted by the next major release. The current LTS release is
1.4.x.
+Q: What Linux kernel versions does each Open vSwitch release work with?
+
+A: The following table lists the Linux kernel versions against which the
+ given versions of the Open vSwitch kernel module will successfully
+ build. The Linux kernel versions are upstream kernel versions, so
+ Linux kernels modified from the upstream sources may not build in
+ some cases even if they are based on a supported version. This is
+ most notably true of Red Hat Enterprise Linux (RHEL) kernels, which
+ are extensively modified from upstream.
+
+ Open vSwitch Linux kernel
+ ------------ -------------
+ 1.4.x 2.6.18 to 3.2
+ 1.5.x 2.6.18 to 3.2
+ 1.6.x 2.6.18 to 3.2
+ 1.7.x 2.6.18 to 3.3
+ 1.8.x 2.6.18 to 3.4
+ 1.9.x 2.6.18 to 3.8
+
+ Open vSwitch userspace should also work with the Linux kernel module
+ built into Linux 3.3 and later.
+
+ Open vSwitch userspace is not sensitive to the Linux kernel version.
+ It should build against almost any kernel, certainly against 2.6.18
+ and later.
+
Q: What features are not available in the Open vSwitch kernel datapath
that ships as part of the upstream Linux kernel?
A: The kernel module in upstream Linux 3.3 and later does not include
the following features:
- - Bridge compatibility, that is, support for the ovs-brcompatd
- daemon that (if you enable it) lets "brctl" and other Linux
- bridge tools transparently work with Open vSwitch instead.
-
- We do not expect bridge compatibility to ever be available in
- upstream Linux. If you need bridge compatibility, use the
- kernel module from the Open vSwitch distribution instead of the
- upstream Linux kernel module.
-
- Tunnel virtual ports, that is, interfaces with type "gre",
"ipsec_gre", "capwap". It is possible to create tunnels in
Linux and attach them to Open vSwitch as system devices.
equally well. Refer to the documentation for the Port table
in ovs-vswitchd.conf.db(5) for more information.
+Q: I added a pair of VMs on different VLANs, like this:
+
+ ovs-vsctl add-br br0
+ ovs-vsctl add-port br0 eth0
+ ovs-vsctl add-port br0 tap0 tag=9
+ ovs-vsctl add-port br0 tap1 tag=10
+
+ but the VMs can't access each other, the external network, or the
+ Internet.
+
+A: It is to be expected that the VMs can't access each other. VLANs
+ are a means to partition a network. When you configured tap0 and
+ tap1 as access ports for different VLANs, you indicated that they
+ should be isolated from each other.
+
+ As for the external network and the Internet, it seems likely that
+ the machines you are trying to access are not on VLAN 9 (or 10) and
+ that the Internet is not available on VLAN 9 (or 10).
+
Q: Can I configure an IP address on a VLAN?
A: Yes. Use an "internal port" configured as an access port. For
Q: What versions of OpenFlow does Open vSwitch support?
-A: Open vSwitch supports OpenFlow 1.0. It also includes a number of
- extensions that bring many of the features from later versions of
- OpenFlow. Work is underway to provide support for later versions and
- can be tracked here:
+A: Open vSwitch 1.9 and earlier support only OpenFlow 1.0 (plus
+ extensions that bring in many of the features from later versions
+ of OpenFlow).
+
+ Open vSwitch versions 1.10 and later will have experimental support
+ for OpenFlow 1.2 and 1.3. On these versions of Open vSwitch, the
+ following command enables OpenFlow 1.0, 1.2, and 1.3 on bridge br0:
+
+ ovs-vsctl set bridge br0 protocols=openflow10,openflow12,openflow13
+
+ Support for OpenFlow 1.1 is incomplete enough that it cannot yet be
+ enabled, even experimentally.
- http://openvswitch.org/development/openflow-1-x-plan/
+ Support for OpenFlow 1.2 and 1.3 is still incomplete. Work to be
+ done is tracked in OPENFLOW-1.1+ in the Open vSwitch source tree
+ (also via http://openvswitch.org/development/openflow-1-x-plan/).
+ When support for a given OpenFlow version is solidly implemented,
+ Open vSwitch will enable that version by default.
Q: I'm getting "error type 45250 code 0". What's that?