datapath-windows: Update OVS_SWITCH_CONTEXT: external and internal port

[cascardo/ovs.git] / FAQ

diff --git a/FAQ b/FAQ
index 3470983..9e74a3f 100644 (file)
--- a/FAQ
+++ b/FAQ
@@ -149,7 +149,7 @@ A: The following table lists the Linux kernel versions against which the
        1.11.x     2.6.18 to 3.8
        2.0.x      2.6.32 to 3.10
        2.1.x      2.6.32 to 3.11
-       2.2.x      2.6.32 to 3.14
+       2.3.x      2.6.32 to 3.14
 
    Open vSwitch userspace should also work with the Linux kernel module
    built into Linux 3.3 and later.
@@ -591,7 +591,7 @@ A: A physical Ethernet device that is part of an Open vSwitch bridge
    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,
@@ -731,6 +731,33 @@ A: It depends on mechanisms and configurations you want to use.
    you want to use ebtables rules.)  On NetBSD, you might want to
    consider using the bridge(4) with BRIDGE_IPF option.
 
+Q: It seems that Open vSwitch does nothing when I removed a port and
+   then immediately put it back.  For example, consider that p1 is
+   a port of type=internal:
+
+       ovs-vsctl del-port br0 p1 -- \
+           add-port br0 p1 -- \
+           set interface p1 type=internal
+
+A: It's an expected behaviour.
+
+   If del-port and add-port happen in a single OVSDB transaction as
+   your example, Open vSwitch always "skips" the intermediate steps.
+   Even if they are done in multiple transactions, it's still allowed
+   for Open vSwitch to skip the intermediate steps and just implement
+   the overall effect.  In both cases, your example would be turned
+   into a no-op.
+
+   If you want to make Open vSwitch actually destroy and then re-create
+   the port for some side effects like resetting kernel setting for the
+   corresponding interface, you need to separate operations into multiple
+   OVSDB transactions and ensure that at least the first one does not have
+   --no-wait.  In the following example, the first ovs-vsctl will block
+   until Open vSwitch reloads the new configuration and removes the port:
+
+       ovs-vsctl del-port br0 p1
+       ovs-vsctl add-port br0 p1 -- \
+           set interface p1 type=internal
 
 Quality of Service (QoS)
 ------------------------
@@ -1239,12 +1266,14 @@ A: Before version 1.11, Open vSwitch did not support MPLS.  That is,
    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?