bfd: Clarify bfd:enable.

[cascardo/ovs.git] / FAQ

diff --git a/FAQ b/FAQ
index 6b4be43..7ef7eb4 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
        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 3.13
+       2.2.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.
 
    Open vSwitch userspace should also work with the Linux kernel module
    built into Linux 3.3 and later.


@@ -158,18 +158,22 @@ A: The following table lists the Linux kernel versions against which the
    It should build against almost any kernel, certainly against 2.6.32
    and later.
 
    It should build against almost any kernel, certainly against 2.6.32
    and later.
 

-Q: What Linux kernel versions does IPFIX flow monitoring work with?
+Q: I get an error like this when I configure Open vSwitch:

 
 

-A: IPFIX flow monitoring requires the Linux kernel module from Open
-   vSwitch version 1.10.90 or later.
+       configure: error: Linux kernel in <dir> is version <x>, but
+       version newer than <y> is not supported (please refer to the
+       FAQ for advice)

 
 

-Q: Should userspace or kernel be upgraded first to minimize downtime?
+   What should I do?

 
 

-   In general, the Open vSwitch userspace should be used with the
-   kernel version included in the same release or with the version
-   from upstream Linux.  However, when upgrading between two releases
-   of Open vSwitch it is best to migrate userspace first to reduce
-   the possibility of incompatibilities.
+A: If there is a newer version of Open vSwitch, consider building that
+   one, because it may support the kernel that you are building
+   against.  (To find out, consult the table in the previous answer.)
+
+   Otherwise, use the Linux kernel module supplied with the kernel
+   that you are using.  All versions of Open vSwitch userspace are
+   compatible with all versions of the Open vSwitch kernel module, so
+   this will also work.  See also the following question.

 
 Q: What features are not available in the Open vSwitch kernel datapath
    that ships as part of the upstream Linux kernel?
 
 Q: What features are not available in the Open vSwitch kernel datapath
    that ships as part of the upstream Linux kernel?


@@ -193,6 +197,19 @@ A: Tunnel virtual ports are not supported, as described in the
    actions.  On Linux kernels before 2.6.39, maximum-sized VLAN packets
    may not be transmitted.
 
    actions.  On Linux kernels before 2.6.39, maximum-sized VLAN packets
    may not be transmitted.
 

+Q: What Linux kernel versions does IPFIX flow monitoring work with?
+
+A: IPFIX flow monitoring requires the Linux kernel module from Open
+   vSwitch version 1.10.90 or later.
+
+Q: Should userspace or kernel be upgraded first to minimize downtime?
+
+   In general, the Open vSwitch userspace should be used with the
+   kernel version included in the same release or with the version
+   from upstream Linux.  However, when upgrading between two releases
+   of Open vSwitch it is best to migrate userspace first to reduce
+   the possibility of incompatibilities.
+

 Q: What happened to the bridge compatibility feature?
 
 A: Bridge compatibility was a feature of Open vSwitch 1.9 and earlier.
 Q: What happened to the bridge compatibility feature?
 
 A: Bridge compatibility was a feature of Open vSwitch 1.9 and earlier.


@@ -258,8 +275,8 @@ A: The following commands configure br0 with eth0 and tap0 as trunk
        ovs-vsctl add-port br0 tap0
        ovs-vsctl add-port br0 tap1 \
            -- --id=@p get port tap1 \
        ovs-vsctl add-port br0 tap0
        ovs-vsctl add-port br0 tap1 \
            -- --id=@p get port tap1 \

-          -- --id=@m create mirror name=m0 select-all=true output-port=@p \
-          -- set bridge br0 mirrors=@m
+           -- --id=@m create mirror name=m0 select-all=true output-port=@p \
+           -- set bridge br0 mirrors=@m

 
    To later disable mirroring, run:
 
 
    To later disable mirroring, run:
 


@@ -313,9 +330,9 @@ A: The following commands configure br0 with eth0 as a trunk port and
        ovs-vsctl add-port br0 eth0
        ovs-vsctl add-port br0 tap0 tag=10
        ovs-vsctl \
        ovs-vsctl add-port br0 eth0
        ovs-vsctl add-port br0 tap0 tag=10
        ovs-vsctl \

-          -- --id=@m create mirror name=m0 select-all=true select-vlan=10 \
+           -- --id=@m create mirror name=m0 select-all=true select-vlan=10 \

                                     output-vlan=15 \
                                     output-vlan=15 \

-          -- set bridge br0 mirrors=@m
+           -- set bridge br0 mirrors=@m

 
    To later disable mirroring, run:
 
 
    To later disable mirroring, run:
 


@@ -363,8 +380,8 @@ A: The following commands configure br0 with eth0 and tap0 as trunk
        ovs-vsctl add-port br0 gre0 \
            -- set interface gre0 type=gre options:remote_ip=192.168.1.10 \
            -- --id=@p get port gre0 \
        ovs-vsctl add-port br0 gre0 \
            -- set interface gre0 type=gre options:remote_ip=192.168.1.10 \
            -- --id=@p get port gre0 \

-          -- --id=@m create mirror name=m0 select-all=true output-port=@p \
-          -- set bridge br0 mirrors=@m
+           -- --id=@m create mirror name=m0 select-all=true output-port=@p \
+           -- set bridge br0 mirrors=@m

 
    To later disable mirroring and destroy the GRE tunnel:
 
 
    To later disable mirroring and destroy the GRE tunnel:
 


@@ -414,6 +431,12 @@ A: First, why do you want to do this?  Two connected bridges are not
    ports will not work with the userspace datapath, only with the
    kernel module.
 
    ports will not work with the userspace datapath, only with the
    kernel module.
 

+Q: How do I configure a bridge without an OpenFlow local port?
+   (Local port in the sense of OFPP_LOCAL)
+
+A: Open vSwitch does not support such a configuration.
+   Bridges always have their local ports.
+

 
 Implementation Details
 ----------------------
 
 Implementation Details
 ----------------------


@@ -653,6 +676,36 @@ A: On Linux kernels before 3.11, the OVS GRE module and Linux GRE module
    can then reload the OVS module following the directions in INSTALL,
    which will ensure that dependencies are satisfied.
 
    can then reload the OVS module following the directions in INSTALL,
    which will ensure that dependencies are satisfied.
 

+Q: Open vSwitch does not seem to obey my packet filter rules.
+
+A: It depends on mechanisms and configurations you want to use.
+
+   You cannot usefully use typical packet filters, like iptables, on
+   physical Ethernet ports that you add to an Open vSwitch bridge.
+   This is because Open vSwitch captures packets from the interface at
+   a layer lower below where typical packet-filter implementations
+   install their hooks.  (This actually applies to any interface of
+   type "system" that you might add to an Open vSwitch bridge.)
+
+   You can usefully use typical packet filters on Open vSwitch
+   internal ports as they are mostly ordinary interfaces from the point
+   of view of packet filters.
+
+   For example, suppose you create a bridge br0 and add Ethernet port
+   eth0 to it.  Then you can usefully add iptables rules to affect the
+   internal interface br0, but not the physical interface eth0.  (br0
+   is also where you would add an IP address, as discussed elsewhere
+   in the FAQ.)
+
+   For simple filtering rules, it might be possible to achieve similar
+   results by installing appropriate OpenFlow flows instead.
+
+   If the use of a particular packet filter setup is essential, Open
+   vSwitch might not be the best choice for you.  On Linux, you might
+   want to consider using the Linux Bridge.  (This is the only choice if
+   you want to use ebtables rules.)  On NetBSD, you might want to
+   consider using the bridge(4) with BRIDGE_IPF option.
+

 
 Quality of Service (QoS)
 ------------------------
 
 Quality of Service (QoS)
 ------------------------


@@ -667,14 +720,14 @@ A: Suppose that you want to set up bridge br0 connected to physical
 
        ovs-vsctl -- \
            add-br br0 -- \
 
        ovs-vsctl -- \
            add-br br0 -- \

-          add-port br0 eth0 -- \
-          add-port br0 vif1.0 -- set interface vif1.0 ofport_request=5 -- \
-          add-port br0 vif2.0 -- set interface vif2.0 ofport_request=6 -- \
-          set port eth0 qos=@newqos -- \
-          --id=@newqos create qos type=linux-htb \
+           add-port br0 eth0 -- \
+           add-port br0 vif1.0 -- set interface vif1.0 ofport_request=5 -- \
+           add-port br0 vif2.0 -- set interface vif2.0 ofport_request=6 -- \
+           set port eth0 qos=@newqos -- \
+           --id=@newqos create qos type=linux-htb \

                other-config:max-rate=1000000000 \
                other-config:max-rate=1000000000 \

-              queues:123=@vif10queue \
-              queues:234=@vif20queue -- \
+               queues:123=@vif10queue \
+               queues:234=@vif20queue -- \

            --id=@vif10queue create queue other-config:max-rate=10000000 -- \
            --id=@vif20queue create queue other-config:max-rate=20000000
 
            --id=@vif10queue create queue other-config:max-rate=10000000 -- \
            --id=@vif20queue create queue other-config:max-rate=20000000
 


@@ -1094,41 +1147,52 @@ Q: What versions of OpenFlow does Open vSwitch support?
 A: The following table lists the versions of OpenFlow supported by
    each version of Open vSwitch:
 
 A: The following table lists the versions of OpenFlow supported by
    each version of Open vSwitch:
 

-       Open vSwitch      OF1.0  OF1.1  OF1.2  OF1.3  OF1.4
-       ===============   =====  =====  =====  =====  =====
-       1.9 and earlier    yes    ---    ---    ---    ---
-       1.10               yes    ---    [*]    [*]    ---
-       1.11               yes    ---    [*]    [*]    ---
-       2.0                yes    [*]    [*]    [*]    ---
-       2.1                yes    [*]    [*]    [*]    ---
-       2.2                yes    [*]    [*]    [*]    [%]
+       Open vSwitch      OF1.0  OF1.1  OF1.2  OF1.3  OF1.4  OF1.5
+       ===============   =====  =====  =====  =====  =====  =====
+       1.9 and earlier    yes    ---    ---    ---    ---    ---
+       1.10               yes    ---    [*]    [*]    ---    ---
+       1.11               yes    ---    [*]    [*]    ---    ---
+       2.0                yes    [*]    [*]    [*]    ---    ---
+       2.1                yes    [*]    [*]    [*]    ---    ---
+       2.2                yes    [*]    [*]    [*]    [%]    [*]
+       2.3                yes    yes    yes    yes    [*]    [*]

 
        [*] Supported, with one or more missing features.
 
        [*] Supported, with one or more missing features.

-       [%] Support is unsafe: ovs-vswitchd will abort when certain
-           unimplemented features are tested.
+       [%] Experimental, unsafe implementation.
+
+   Open vSwitch 2.3 enables OpenFlow 1.0, 1.1, 1.2, and 1.3 by default
+   in ovs-vswitchd.  In Open vSwitch 1.10 through 2.2, OpenFlow 1.1,
+   1.2, and 1.3 must be enabled manually in ovs-vswitchd.  OpenFlow
+   1.4 and 1.5 are also supported, with missing features, in Open
+   vSwitch 2.3 and later, but not enabled by default.  In any case,
+   the user may override the default:
+
+       - To enable OpenFlow 1.0, 1.1, 1.2, and 1.3 on bridge br0:
+
+         ovs-vsctl set bridge br0 protocols=OpenFlow10,OpenFlow11,OpenFlow12,OpenFlow13
+
+       - To enable OpenFlow 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5 on bridge br0:
+
+         ovs-vsctl set bridge br0 protocols=OpenFlow10,OpenFlow11,OpenFlow12,OpenFlow13,OpenFlow14,OpenFlow15

 
 

-   Because of missing features, OpenFlow 1.1, 1.2, and 1.3 must be
-   enabled manually.  The following command enables OpenFlow 1.0, 1.1,
-   1.2, and 1.3 on bridge br0:
+       - To enable only OpenFlow 1.0 on bridge br0:

 
 

-       ovs-vsctl set bridge br0 protocols=OpenFlow10,OpenFlow11,OpenFlow12,OpenFlow13
+         ovs-vsctl set bridge br0 protocols=OpenFlow10

 
 

-   Use the -O option to enable support for later versions of OpenFlow
-   in ovs-ofctl.  For example:
+   All current versions of ovs-ofctl enable only OpenFlow 1.0 by
+   default.  Use the -O option to enable support for later versions of
+   OpenFlow in ovs-ofctl.  For example:

 
        ovs-ofctl -O OpenFlow13 dump-flows br0
 
 
        ovs-ofctl -O OpenFlow13 dump-flows br0
 

-   OpenFlow 1.4 is a special case, because it is not implemented
-   safely: ovs-vswitchd will abort when certain unimplemented features
-   are tested.  Thus, for now it is suitable only for experimental
-   use.  ovs-vswitchd will only allow OpenFlow 1.4 to be enabled
-   (which must be done in the same way described above) when it is
-   invoked with a special --enable-of14 command line option.
+   (Open vSwitch 2.2 had an experimental implementation of OpenFlow
+   1.4 that could cause crashes.  We don't recommend enabling it.)

 
    OPENFLOW-1.1+ in the Open vSwitch source tree tracks support for
 
    OPENFLOW-1.1+ in the Open vSwitch source tree tracks support for

-   OpenFlow 1.1 and later features.  When support for a given OpenFlow
-   version is solidly implemented, Open vSwitch will enable that
-   version by default.
+   OpenFlow 1.1 and later features.  When support for OpenFlow 1.4 and
+   1.5 is solidly implemented, Open vSwitch will enable those version
+   by default.  Also, the OpenFlow 1.5 specification is still under
+   development and thus subject to change.

 
 Q: Does Open vSwitch support MPLS?
 
 
 Q: Does Open vSwitch support MPLS?