Linux release or using the kernel module paired with the userspace
distribution.
+Q: Why do tunnels not work when using a kernel module other than the
+ one packaged with Open vSwitch?
+
+A: Support for tunnels was added to the upstream Linux kernel module
+ after the rest of Open vSwitch. As a result, some kernels may contain
+ support for Open vSwitch but not tunnels. The minimum kernel version
+ that supports each tunnel protocol is:
+
+ Protocol Linux Kernel
+ -------- ------------
+ GRE 3.11
+ VXLAN 3.12
+ LISP <not upstream>
+
+ If you are using a version of the kernel that is older than the one
+ listed above, it is still possible to use that tunnel protocol. However,
+ you must compile and install the kernel module included with the Open
+ vSwitch distribution rather than the one on your machine. If problems
+ persist after doing this, check to make sure that the module that is
+ loaded is the one you expect.
+
Q: What features are not available when using the userspace datapath?
A: Tunnel virtual ports are not supported, as described in the
dumps datapath flows for only the specified bridge, regardless
of the type.
+Q: How does multicast snooping works with VLANs?
+
+A: Open vSwitch maintains snooping tables for each VLAN.
+
Performance
-----------
versions of Linux that Open vSwitch supports.
By the way, this issue is not specific to physical Ethernet
- devices. It applies to all network devices except Open vswitch
+ devices. It applies to all network devices except Open vSwitch
"internal" devices.
Q: I created a bridge and added a couple of Ethernet ports to it,
OpenFlow controller doesn't see the VLANs that I expect," and you
can refer to the answer there for more information.
+Q: How MAC learning works with VLANs?
+
+A: Open vSwitch implements Independent VLAN Learning (IVL) for
+ OFPP_NORMAL action. I.e. it logically has separate learning tables
+ for each VLANs.
+
VXLANs
-----
packet. Kernel datapath support is unchanged from earlier
versions.
- Open vSwitch version 2.2 will be able to match, push, or pop up to
- 3 MPLS labels. Looking past MPLS labels into the encapsulated
- packet will still be unsupported. Both userspace and kernel
- datapaths will be supported, but MPLS processing always happens in
- userspace either way, so kernel datapath performance will be
- disappointing.
+ Open vSwitch version 2.3 can match, push, or pop up to 3 MPLS
+ labels. Looking past MPLS labels into the encapsulated packet will
+ still be unsupported. Both userspace and kernel datapaths will be
+ supported, but MPLS processing always happens in userspace either
+ way, so kernel datapath performance will be disappointing.
+
+ Open vSwitch version 2.4 will have kernel support for MPLS,
+ yielding improved performance.
Q: I'm getting "error type 45250 code 0". What's that?