netlink-notifier: Support multiple groups.

[cascardo/ovs.git] / FAQ.md

diff --git a/FAQ.md b/FAQ.md
index e39a57f..df6f225 100644 (file)
--- a/FAQ.md
+++ b/FAQ.md
@@ -180,13 +180,10 @@ A: Open vSwitch supports different datapaths on different platforms.  Each
                        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.
+                       distributed with the OVS source tree.
 
    * *Userspace*: Also known as DPDK, dpif-netdev or dummy datapath. It is the
-                  only datapath that works on NetBSD and FreeBSD.
+                  only datapath that works on NetBSD, FreeBSD and Mac OSX.
 
    * *Hyper-V*: Also known as the Windows datapath.
 
@@ -195,9 +192,10 @@ A: Open vSwitch supports different datapaths on different platforms.  Each
 
 Feature               | Linux upstream | Linux OVS tree | Userspace | Hyper-V |
 ----------------------|:--------------:|:--------------:|:---------:|:-------:|
-Connection tracking   |      4.3       |       3.10     |    NO     |   NO    |
+NAT                   |      4.6       |       NO       |    NO     |   NO    |
+Connection tracking   |      4.3       |       YES      |    NO     | PARTIAL |
 Tunnel - LISP         |      NO        |       YES      |    NO     |   NO    |
-Tunnel - STT          |      NO        |       3.5      |    NO     |   YES   |
+Tunnel - STT          |      NO        |       YES      |    NO     |   YES   |
 Tunnel - GRE          |      3.11      |       YES      |    YES    |   YES   |
 Tunnel - VXLAN        |      3.12      |       YES      |    YES    |   YES   |
 Tunnel - Geneve       |      3.18      |       YES      |    YES    |   NO    |
@@ -2014,6 +2012,23 @@ A: In Open vSwitch 2.3 and earlier, Open vSwitch used the destination
    vSwitch source tree.  (OpenFlow 1.5 support in Open vSwitch is still
    experimental.)
 
+### Q: I added a flow to accept packets on VLAN 123 and output them on
+   VLAN 456, like so:
+
+       ovs-ofctl add-flow br0 dl_vlan=123,actions=output:1,mod_vlan_vid:456
+
+   but the packets are actually being output in VLAN 123.  Why?
+
+A: OpenFlow actions are executed in the order specified.  Thus, the
+   actions above first output the packet, then change its VLAN.  Since
+   the output occurs before changing the VLAN, the change in VLAN will
+   have no visible effect.
+
+   To solve this and similar problems, order actions so that changes
+   to headers happen before output, e.g.:
+
+       ovs-ofctl add-flow br0 dl_vlan=123,actions=mod_vlan_vid:456,output:1
+
 
 Development
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