It should build against almost any kernel, certainly against 2.6.32
and later.
+### Q: Are all features available with all datapaths?
+
+A: Open vSwitch supports different datapaths on different platforms. Each
+ datapath has a different feature set: the following tables try to summarize
+ the status.
+
+ Supported datapaths:
+
+ * *Linux upstream*: The datapath implemented by the kernel module shipped
+ with Linux upstream. Since features have been gradually
+ introduced into the kernel, the table mentions the first
+ Linux release whose OVS module supports the feature.
+
+ * *Linux OVS tree*: The datapath implemented by the Linux kernel module
+ distributed with the OVS source tree. Some features of
+ this module rely on functionality not available in older
+ kernels: in this case the minumum Linux version (against
+ which the feature can be compiled) is listed.
+
+ * *Userspace*: Also known as DPDK, dpif-netdev or dummy datapath. It is the
+ only datapath that works on NetBSD and FreeBSD.
+
+ * *Hyper-V*: Also known as the Windows datapath.
+
+ The following table lists the datapath supported features from
+ an Open vSwitch user's perspective.
+
+Feature | Linux upstream | Linux OVS tree | Userspace | Hyper-V |
+----------------------|:--------------:|:--------------:|:---------:|:-------:|
+Connection tracking | 4.3 | 3.10 | NO | NO |
+Tunnel - LISP | NO | YES | NO | NO |
+Tunnel - STT | NO | 3.5 | NO | YES |
+Tunnel - GRE | 3.11 | YES | YES | YES |
+Tunnel - VXLAN | 3.12 | YES | YES | YES |
+Tunnel - Geneve | 3.18 | YES | YES | NO |
+QoS - Policing | YES | YES | NO | NO |
+QoS - Shaping | YES | YES | NO | NO |
+sFlow | YES | YES | YES | NO |
+Set action | YES | YES | YES | PARTIAL |
+NIC Bonding | YES | YES | YES | NO |
+Multiple VTEPs | YES | YES | YES | NO |
+
+ **Notes:**
+ * Only a limited set of flow fields is modifiable via the set action by the
+ Hyper-V datapath.
+ * The Hyper-V datapath only supports one physical NIC per datapath. This is
+ why bonding is not supported.
+ * The Hyper-V datapath can have at most one IP address configured as a
+ tunnel endpoint.
+
+ The following table lists features that do not *directly* impact an
+ Open vSwitch user, e.g. because their absence can be hidden by the ofproto
+ layer (usually this comes with a performance penalty).
+
+Feature | Linux upstream | Linux OVS tree | Userspace | Hyper-V |
+----------------------|:--------------:|:--------------:|:---------:|:-------:|
+SCTP flows | 3.12 | YES | YES | YES |
+MPLS | 3.19 | YES | YES | NO |
+UFID | 4.0 | YES | YES | NO |
+Megaflows | 3.12 | YES | YES | NO |
+Masked set action | 4.0 | YES | YES | NO |
+Recirculation | 3.19 | YES | YES | NO |
+TCP flags matching | 3.13 | YES | YES | NO |
+Validate flow actions | YES | YES | N/A | NO |
+Multiple datapaths | YES | YES | YES | NO |
+Tunnel TSO - STT | N/A | YES | NO | YES |
+
### Q: I get an error like this when I configure Open vSwitch:
configure: error: Linux kernel in <dir> is version <x>, but