A database with this schema holds the configuration for one Open
vSwitch daemon. The top-level configuration for the daemon is the
table, which must have exactly one
record. Records in other tables are significant only when they
can be reached directly or indirectly from the table. Records that are not reachable from
the table are automatically deleted
from the database, except for records in a few distinguished
``root set'' tables.
A port within a .
Most commonly, a port has exactly one ``interface,'' pointed to by its
column. Such a port logically
corresponds to a port on a physical Ethernet switch. A port
with more than one interface is a ``bonded port'' (see
).
Some properties that one might think as belonging to a port are actually
part of the port's members.
Port name. Should be alphanumeric and no more than about 8
bytes long. May be the same as the interface name, for
non-bonded ports. Must otherwise be unique among the names of
ports, interfaces, and bridges on a host.
The port's interfaces. If there is more than one, this is a
bonded Port.
Bridge ports support the following types of VLAN configuration:
- trunk
-
A trunk port carries packets on one or more specified VLANs
specified in the column (often, on every
VLAN). A packet that ingresses on a trunk port is in the VLAN
specified in its 802.1Q header, or VLAN 0 if the packet has no
802.1Q header. A packet that egresses through a trunk port will
have an 802.1Q header if it has a nonzero VLAN ID.
Any packet that ingresses on a trunk port tagged with a VLAN that
the port does not trunk is dropped.
- access
-
An access port carries packets on exactly one VLAN specified in the
column. Packets egressing on an access port
have no 802.1Q header.
Any packet with an 802.1Q header with a nonzero VLAN ID that
ingresses on an access port is dropped, regardless of whether the
VLAN ID in the header is the access port's VLAN ID.
- native-tagged
-
A native-tagged port resembles a trunk port, with the exception that
a packet without an 802.1Q header that ingresses on a native-tagged
port is in the ``native VLAN'' (specified in the
column).
- native-untagged
-
A native-untagged port resembles a native-tagged port, with the
exception that a packet that egresses on a native-untagged port in
the native VLAN will not have an 802.1Q header.
A packet will only egress through bridge ports that carry the VLAN of
the packet, as described by the rules above.
The VLAN mode of the port, as described above. When this column is
empty, a default mode is selected as follows:
-
If
contains a value, the port is an access
port. The column should be empty.
-
Otherwise, the port is a trunk port. The
column value is honored if it is present.
For an access port, the port's implicitly tagged VLAN. For a
native-tagged or native-untagged port, the port's native VLAN. Must
be empty if this is a trunk port.
For a trunk, native-tagged, or native-untagged port, the 802.1Q VLAN
or VLANs that this port trunks; if it is empty, then the port trunks
all VLANs. Must be empty if this is an access port.
A native-tagged or native-untagged port always trunks its native
VLAN, regardless of whether includes that
VLAN.
An 802.1Q header contains two important pieces of information: a VLAN
ID and a priority. A frame with a zero VLAN ID, called a
``priority-tagged'' frame, is supposed to be treated the same way as
a frame without an 802.1Q header at all (except for the priority).
However, some network elements ignore any frame that has 802.1Q
header at all, even when the VLAN ID is zero. Therefore, by default
Open vSwitch does not output priority-tagged frames, instead omitting
the 802.1Q header entirely if the VLAN ID is zero. Set this key to
true
to enable priority-tagged frames on a port.
Regardless of this setting, Open vSwitch omits the 802.1Q header on
output if both the VLAN ID and priority would be zero.
All frames output to native-tagged ports have a nonzero VLAN ID, so
this setting is not meaningful on native-tagged ports.
A port that has more than one interface is a ``bonded port.'' Bonding
allows for load balancing and fail-over. Some kinds of bonding will
work with any kind of upstream switch:
balance-slb
-
Balances flows among slaves based on source MAC address and output
VLAN, with periodic rebalancing as traffic patterns change.
active-backup
-
Assigns all flows to one slave, failing over to a backup slave when
the active slave is disabled.
The following modes require the upstream switch to support 802.3ad with
successful LACP negotiation:
balance-tcp
-
Balances flows among slaves based on L2, L3, and L4 protocol
information such as destination MAC address, IP address, and TCP
port.
stable
-
Attempts to always assign a given flow to the same slave
consistently. In an effort to maintain stability, no load
balancing is done. Uses a similar hashing strategy to
balance-tcp
, always taking into account L3 and L4
fields even if LACP negotiations are unsuccessful.
Slave selection decisions are made based on if set. Otherwise,
OpenFlow port number is used. Decisions are consistent across all
ovs-vswitchd
instances with equivalent
values.
These columns apply only to bonded ports. Their values are
otherwise ignored.
The type of bonding used for a bonded port. Defaults to
active-backup
if unset.
An integer hashed along with flows when choosing output slaves in load
balanced bonds. When changed, all flows will be assigned different
hash values possibly causing slave selection decisions to change. Does
not affect bonding modes which do not employ load balancing such as
active-backup
.
An important part of link bonding is detecting that links are down so
that they may be disabled. These settings determine how Open vSwitch
detects link failure.
The means used to detect link failures. Defaults to
carrier
which uses each interface's carrier to detect
failures. When set to miimon
, will check for failures
by polling each interface's MII.
The interval, in milliseconds, between successive attempts to poll
each interface's MII. Relevant only when is miimon
.
The number of milliseconds for which carrier must stay up on an
interface before the interface is considered to be up. Specify
0
to enable the interface immediately.
This setting is honored only when at least one bonded interface is
already enabled. When no interfaces are enabled, then the first
bond interface to come up is enabled immediately.
The number of milliseconds for which carrier must stay down on an
interface before the interface is considered to be down. Specify
0
to disable the interface immediately.
LACP, the Link Aggregation Control Protocol, is an IEEE standard that
allows switches to automatically detect that they are connected by
multiple links and aggregate across those links. These settings
control LACP behavior.
Configures LACP on this port. LACP allows directly connected
switches to negotiate which links may be bonded. LACP may be enabled
on non-bonded ports for the benefit of any switches they may be
connected to. active
ports are allowed to initiate LACP
negotiations. passive
ports are allowed to participate
in LACP negotiations initiated by a remote switch, but not allowed to
initiate such negotiations themselves. If LACP is enabled on a port
whose partner switch does not support LACP, the bond will be
disabled. Defaults to off
if unset.
The LACP system ID of this . The system ID of a
LACP bond is used to identify itself to its partners. Must be a
nonzero MAC address. Defaults to the bridge Ethernet address if
unset.
The LACP system priority of this . In LACP
negotiations, link status decisions are made by the system with the
numerically lower priority.
The LACP timing which should be used on this .
By default slow
is used. When configured to be
fast
LACP heartbeats are requested at a rate of once
per second causing connectivity problems to be detected more
quickly. In slow
mode, heartbeats are requested at a
rate of once every 30 seconds.
These settings control behavior when a bond is in
balance-slb
mode, regardless of whether the bond was
intentionally configured in SLB mode or it fell back to SLB mode
because LACP negotiation failed.
For a load balanced bonded port, the number of milliseconds between
successive attempts to rebalance the bond, that is, to move flows
from one interface on the bond to another in an attempt to keep usage
of each interface roughly equal. If zero, load balancing is disabled
on the bond (carrier status changes still cause flows to move). If
less than 1000ms, the rebalance interval will be 1000ms.
For a bonded port, whether to create a fake internal interface with the
name of the port. Use only for compatibility with legacy software that
requires this.
If spanning tree is enabled on the bridge, member ports are
enabled by default (with the exception of bond, internal, and
mirror ports which do not work with STP). If this column's
value is false
spanning tree is disabled on the
port.
The port number used for the lower 8 bits of the port-id. By
default, the numbers will be assigned automatically. If any
port's number is manually configured on a bridge, then they
must all be.
The port's relative priority value for determining the root
port (the upper 8 bits of the port-id). A port with a lower
port-id will be chosen as the root port. By default, the
priority is 0x80.
Spanning tree path cost for the port. A lower number indicates
a faster link. By default, the cost is based on the maximum
speed of the link.
Quality of Service configuration for this port.
The MAC address to use for this port for the purpose of choosing the
bridge's MAC address. This column does not necessarily reflect the
port's actual MAC address, nor will setting it change the port's actual
MAC address.
Does this port represent a sub-bridge for its tagged VLAN within the
Bridge? See ovs-vsctl(8) for more information.
External IDs for a fake bridge (see the
column) are defined by prefixing a key with
fake-bridge-
,
e.g. fake-bridge-xs-network-uuids
.
Status information about ports attached to bridges.
Key-value pairs that report port status.
The port-id (in hex) used in spanning tree advertisements for
this port. Configuring the port-id is described in the
stp-port-num
and stp-port-priority
keys of the other_config
section earlier.
STP state of the port.
The amount of time (in seconds) port has been in the current
STP state.
STP role of the port.
Key-value pairs that report port statistics.
Number of STP BPDUs sent on this port by the spanning
tree library.
Number of STP BPDUs received on this port and accepted by the
spanning tree library.
Number of bad STP BPDUs received on this port. Bad BPDUs
include runt packets and those with an unexpected protocol ID.
The overall purpose of these columns is described under Common
Columns
at the beginning of this document.
An interface within a .
Interface name. Should be alphanumeric and no more than about 8 bytes
long. May be the same as the port name, for non-bonded ports. Must
otherwise be unique among the names of ports, interfaces, and bridges
on a host.
Ethernet address to set for this interface. If unset then the
default MAC address is used:
- For the local interface, the default is the lowest-numbered MAC
address among the other bridge ports, either the value of the
in its record,
if set, or its actual MAC (for bonded ports, the MAC of its slave
whose name is first in alphabetical order). Internal ports and
bridge ports that are used as port mirroring destinations (see the
table) are ignored.
- For other internal interfaces, the default MAC is randomly
generated.
- External interfaces typically have a MAC address associated with
their hardware.
Some interfaces may not have a software-controllable MAC
address.
OpenFlow port number for this interface. Unlike most columns, this
column's value should be set only by Open vSwitch itself. Other
clients should set this column to an empty set (the default) when
creating an .
Open vSwitch populates this column when the port number becomes
known. If the interface is successfully added,
will be set to a number between 1 and 65535
(generally either in the range 1 to 65279, inclusive, or 65534, the
port number for the OpenFlow ``local port''). If the interface
cannot be added then Open vSwitch sets this column
to -1.
The interface type, one of:
system
- An ordinary network device, e.g.
eth0
on Linux.
Sometimes referred to as ``external interfaces'' since they are
generally connected to hardware external to that on which the Open
vSwitch is running. The empty string is a synonym for
system
.
internal
- A simulated network device that sends and receives traffic. An
internal interface whose
is the same as its
bridge's is called the
``local interface.'' It does not make sense to bond an internal
interface, so the terms ``port'' and ``interface'' are often used
imprecisely for internal interfaces.
tap
- A TUN/TAP device managed by Open vSwitch.
gre
-
An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4
tunnel. See
for information on
configuring GRE tunnels.
ipsec_gre
-
An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4
IPsec tunnel.
capwap
-
An Ethernet tunnel over the UDP transport portion of CAPWAP (RFC
5415). This allows interoperability with certain switches that do
not support GRE. Only the tunneling component of the protocol is
implemented. UDP ports 58881 and 58882 are used as the source and
destination ports respectively. CAPWAP is currently supported only
with the Linux kernel datapath with kernel version 2.6.26 or later.
patch
-
A pair of virtual devices that act as a patch cable.
null
- An ignored interface.
These options apply to interfaces with of
gre
, ipsec_gre
, and capwap
.
Each tunnel must be uniquely identified by the combination of , , , and . If two ports are defined that are the same except one
has an optional identifier and the other does not, the more specific
one is matched first. is
considered more specific than if
a port defines one and another port defines the other.
Required. The tunnel endpoint. Unicast and multicast endpoints are
both supported.
When a multicast endpoint is specified, a routing table lookup occurs
only when the tunnel is created. Following a routing change, delete
and then re-create the tunnel to force a new routing table lookup.
Optional. The destination IP that received packets must match.
Default is to match all addresses. Must be omitted when is a multicast address.
Optional. The key that received packets must contain, one of:
-
0
. The tunnel receives packets with no key or with a
key of 0. This is equivalent to specifying no at all.
-
A positive 32-bit (for GRE) or 64-bit (for CAPWAP) number. The
tunnel receives only packets with the specified key.
-
The word
flow
. The tunnel accepts packets with any
key. The key will be placed in the tun_id
field for
matching in the flow table. The ovs-ofctl
manual page
contains additional information about matching fields in OpenFlow
flows.
Optional. The key to be set on outgoing packets, one of:
-
0
. Packets sent through the tunnel will have no key.
This is equivalent to specifying no at all.
-
A positive 32-bit (for GRE) or 64-bit (for CAPWAP) number. Packets
sent through the tunnel will have the specified key.
-
The word
flow
. Packets sent through the tunnel will
have the key set using the set_tunnel
Nicira OpenFlow
vendor extension (0 is used in the absence of an action). The
ovs-ofctl
manual page contains additional information
about the Nicira OpenFlow vendor extensions.
Optional. Shorthand to set in_key
and
out_key
at the same time.
Optional. The value of the ToS bits to be set on the encapsulating
packet. It may also be the word inherit
, in which case
the ToS will be copied from the inner packet if it is IPv4 or IPv6
(otherwise it will be 0). The ECN fields are always inherited.
Default is 0.
Optional. The TTL to be set on the encapsulating packet. It may also
be the word inherit
, in which case the TTL will be copied
from the inner packet if it is IPv4 or IPv6 (otherwise it will be the
system default, typically 64). Default is the system default TTL.
Optional. If enabled, the Don't Fragment bit will be copied from the
inner IP headers (those of the encapsulated traffic) to the outer
(tunnel) headers. Default is disabled; set to true
to
enable.
Optional. If enabled, the Don't Fragment bit will be set by default on
tunnel headers if the df_inherit
option is not set, or if
the encapsulated packet is not IP. Default is enabled; set to
false
to disable.
Optional. Enable tunnel path MTU discovery. If enabled ``ICMP
Destination Unreachable - Fragmentation Needed'' messages will be
generated for IPv4 packets with the DF bit set and IPv6 packets above
the minimum MTU if the packet size exceeds the path MTU minus the size
of the tunnel headers. Note that this option causes behavior that is
typically reserved for routers and therefore is not entirely in
compliance with the IEEE 802.1D specification for bridges. Default is
enabled; set to false
to disable.
Only gre
interfaces support these options.
Enable caching of tunnel headers and the output path. This can lead
to a significant performance increase without changing behavior. In
general it should not be necessary to adjust this setting. However,
the caching can bypass certain components of the IP stack (such as
iptables
) and it may be useful to disable it if these
features are required or as a debugging measure. Default is enabled,
set to false
to disable.
Only gre
and ipsec_gre
interfaces support
these options.
Optional. Compute GRE checksums on outgoing packets. Default is
disabled, set to true
to enable. Checksums present on
incoming packets will be validated regardless of this setting.
GRE checksums impose a significant performance penalty because they
cover the entire packet. The encapsulated L3, L4, and L7 packet
contents typically have their own checksums, so this additional
checksum only adds value for the GRE and encapsulated L2 headers.
This option is supported for ipsec_gre
, but not useful
because GRE checksums are weaker than, and redundant with, IPsec
payload authentication.
Only ipsec_gre
interfaces support these options.
Required for certificate authentication. A string containing the
peer's certificate in PEM format. Additionally the host's
certificate must be specified with the certificate
option.
Required for certificate authentication. The name of a PEM file
containing a certificate that will be presented to the peer during
authentication.
Optional for certificate authentication. The name of a PEM file
containing the private key associated with certificate
.
If certificate
contains the private key, this option may
be omitted.
Required for pre-shared key authentication. Specifies a pre-shared
key for authentication that must be identical on both sides of the
tunnel.
Only patch
interfaces support these options.
The of the for the other
side of the patch. The named 's own
peer
option must specify this 's
name. That is, the two patch interfaces must have reversed and peer
values.
Status information about interfaces attached to bridges, updated every
5 seconds. Not all interfaces have all of these properties; virtual
interfaces don't have a link speed, for example. Non-applicable
columns will have empty values.
The administrative state of the physical network link.
The observed state of the physical network link. This is ordinarily
the link's carrier status. If the interface's is
a bond configured for miimon monitoring, it is instead the network
link's miimon status.
The number of times Open vSwitch has observed the
of this change.
The negotiated speed of the physical network link.
Valid values are positive integers greater than 0.
The duplex mode of the physical network link.
The MTU (maximum transmission unit); i.e. the largest
amount of data that can fit into a single Ethernet frame.
The standard Ethernet MTU is 1500 bytes. Some physical media
and many kinds of virtual interfaces can be configured with
higher MTUs.
This column will be empty for an interface that does not
have an MTU as, for example, some kinds of tunnels do not.
Boolean value indicating LACP status for this interface. If true, this
interface has current LACP information about its LACP partner. This
information may be used to monitor the health of interfaces in a LACP
enabled port. This column will be empty if LACP is not enabled.
Key-value pairs that report port status. Supported status values are
-dependent; some interfaces may not have a valid
, for example.
The name of the device driver controlling the network adapter.
The version string of the device driver controlling the network
adapter.
The version string of the network adapter's firmware, if available.
The source IP address used for an IPv4 tunnel end-point, such as
gre
or capwap
.
Egress interface for tunnels. Currently only relevant for GRE and
CAPWAP tunnels. On Linux systems, this column will show the name of
the interface which is responsible for routing traffic destined for the
configured . This could be an
internal interface such as a bridge port.
Whether carrier is detected on .
Key-value pairs that report interface statistics. The current
implementation updates these counters periodically. Future
implementations may update them when an interface is created, when they
are queried (e.g. using an OVSDB select
operation), and
just before an interface is deleted due to virtual interface hot-unplug
or VM shutdown, and perhaps at other times, but not on any regular
periodic basis.
These are the same statistics reported by OpenFlow in its struct
ofp_port_stats
structure. If an interface does not support a
given statistic, then that pair is omitted.
Number of received packets.
Number of received bytes.
Number of transmitted packets.
Number of transmitted bytes.
Number of packets dropped by RX.
Number of frame alignment errors.
Number of packets with RX overrun.
Number of CRC errors.
Total number of receive errors, greater than or equal to the sum of
the above.
Number of packets dropped by TX.
Number of collisions.
Total number of transmit errors, greater than or equal to the sum of
the above.
These settings control ingress policing for packets received on this
interface. On a physical interface, this limits the rate at which
traffic is allowed into the system from the outside; on a virtual
interface (one connected to a virtual machine), this limits the rate at
which the VM is able to transmit.
Policing is a simple form of quality-of-service that simply drops
packets received in excess of the configured rate. Due to its
simplicity, policing is usually less accurate and less effective than
egress QoS (which is configured using the and tables).
Policing is currently implemented only on Linux. The Linux
implementation uses a simple ``token bucket'' approach:
-
The size of the bucket corresponds to
. Initially the bucket is full.
-
Whenever a packet is received, its size (converted to tokens) is
compared to the number of tokens currently in the bucket. If the
required number of tokens are available, they are removed and the
packet is forwarded. Otherwise, the packet is dropped.
-
Whenever it is not full, the bucket is refilled with tokens at the
rate specified by
.
Policing interacts badly with some network protocols, and especially
with fragmented IP packets. Suppose that there is enough network
activity to keep the bucket nearly empty all the time. Then this token
bucket algorithm will forward a single packet every so often, with the
period depending on packet size and on the configured rate. All of the
fragments of an IP packets are normally transmitted back-to-back, as a
group. In such a situation, therefore, only one of these fragments
will be forwarded and the rest will be dropped. IP does not provide
any way for the intended recipient to ask for only the remaining
fragments. In such a case there are two likely possibilities for what
will happen next: either all of the fragments will eventually be
retransmitted (as TCP will do), in which case the same problem will
recur, or the sender will not realize that its packet has been dropped
and data will simply be lost (as some UDP-based protocols will do).
Either way, it is possible that no forward progress will ever occur.
Maximum rate for data received on this interface, in kbps. Data
received faster than this rate is dropped. Set to 0
(the default) to disable policing.
Maximum burst size for data received on this interface, in kb. The
default burst size if set to 0
is 1000 kb. This value
has no effect if
is 0
.
Specifying a larger burst size lets the algorithm be more forgiving,
which is important for protocols like TCP that react severely to
dropped packets. The burst size should be at least the size of the
interface's MTU. Specifying a value that is numerically at least as
large as 10% of helps TCP come
closer to achieving the full rate.
802.1ag Connectivity Fault Management (CFM) allows a group of
Maintenance Points (MPs) called a Maintenance Association (MA) to
detect connectivity problems with each other. MPs within a MA should
have complete and exclusive interconnectivity. This is verified by
occasionally broadcasting Continuity Check Messages (CCMs) at a
configurable transmission interval.
According to the 802.1ag specification, each Maintenance Point should
be configured out-of-band with a list of Remote Maintenance Points it
should have connectivity to. Open vSwitch differs from the
specification in this area. It simply assumes the link is faulted if
no Remote Maintenance Points are reachable, and considers it not
faulted otherwise.
A Maintenance Point ID (MPID) uniquely identifies each endpoint within
a Maintenance Association. The MPID is used to identify this endpoint
to other Maintenance Points in the MA. Each end of a link being
monitored should have a different MPID. Must be configured to enable
CFM on this .
Indicates a connectivity fault triggered by an inability to receive
heartbeats from any remote endpoint. When a fault is triggered on
s participating in bonds, they will be
disabled.
Faults can be triggered for several reasons. Most importantly they
are triggered when no CCMs are received for a period of 3.5 times the
transmission interval. Faults are also triggered when any CCMs
indicate that a Remote Maintenance Point is not receiving CCMs but
able to send them. Finally, a fault is triggered if a CCM is
received which indicates unexpected configuration. Notably, this
case arises when a CCM is received which advertises the local MPID.
Indicates a CFM fault was triggered due to a lack of CCMs received on
the .
Indicates a CFM fault was triggered due to the reception of a CCM with
the RDI bit flagged. Endpoints set the RDI bit in their CCMs when they
are not receiving CCMs themselves. This typically indicates a
unidirectional connectivity failure.
Indicates a CFM fault was triggered due to the reception of a CCM with
a MAID other than the one Open vSwitch uses. CFM broadcasts are tagged
with an identification number in addition to the MPID called the MAID.
Open vSwitch only supports receiving CCM broadcasts tagged with the
MAID it uses internally.
Indicates a CFM fault was triggered due to the reception of a CCM
advertising the same MPID configured in the
column of this . This may indicate a loop in
the network.
Indicates a CFM fault was triggered because the CFM module received
CCMs from more remote endpoints than it can keep track of.
Indicates a CFM fault was manually triggered by an administrator using
an ovs-appctl
command.
Indicates a CFM fault was triggered due to the reception of a CCM
frame having an invalid interval.
Indicates a CFM fault was triggered because the CFM module received
a CCM frame with a sequence number that it was not expecting.
Indicates the health of the interface as a percentage of CCM frames
received over 21 s.
The health of an interface is undefined if it is communicating with
more than one . It reduces if
healthy heartbeats are not received at the expected rate, and
gradually improves as healthy heartbeats are received at the desired
rate. Every 21 s, the
health of the interface is refreshed.
As mentioned above, the faults can be triggered for several reasons.
The link health will deteriorate even if heartbeats are received but
they are reported to be unhealthy. An unhealthy heartbeat in this
context is a heartbeat for which either some fault is set or is out
of sequence. The interface health can be 100 only on receiving
healthy heartbeats at the desired rate.
When CFM is properly configured, Open vSwitch will occasionally
receive CCM broadcasts. These broadcasts contain the MPID of the
sending Maintenance Point. The list of MPIDs from which this
is receiving broadcasts from is regularly
collected and written to this column.
The interval, in milliseconds, between transmissions of CFM
heartbeats. Three missed heartbeat receptions indicate a
connectivity fault.
In standard operation only intervals of 3, 10, 100, 1,000, 10,000,
60,000, or 600,000 ms are supported. Other values will be rounded
down to the nearest value on the list. Extended mode (see ) supports any interval up
to 65,535 ms. In either mode, the default is 1000 ms.
We do not recommend using intervals less than 100 ms.
When true
, the CFM module operates in extended mode. This
causes it to use a nonstandard destination address to avoid conflicting
with compliant implementations which may be running concurrently on the
network. Furthermore, extended mode increases the accuracy of the
cfm_interval
configuration parameter by breaking wire
compatibility with 802.1ag compliant implementations. Defaults to
false
.
When down
, the CFM module marks all CCMs it generates as
operationally down without triggering a fault. This allows remote
maintenance points to choose not to forward traffic to the
on which this CFM module is running.
Currently, in Open vSwitch, the opdown bit of CCMs affects
s participating in bonds, and the bundle
OpenFlow action. This setting is ignored when CFM is not in extended
mode. Defaults to up
.
When set, the CFM module will apply a VLAN tag to all CCMs it generates
with the given value. May be the string random
in which
case each CCM will be tagged with a different randomly generated VLAN.
When set, the CFM module will apply a VLAN tag to all CCMs it generates
with the given PCP value. The VLAN ID of the tag is governed by the
value of . If
is unset, a VLAN ID of
zero is used.
Used in stable
bond mode to make slave
selection decisions. Allocating values consistently across interfaces
participating in a bond will guarantee consistent slave selection
decisions across ovs-vswitchd
instances when using
stable
bonding mode.
The LACP port ID of this . Port IDs are
used in LACP negotiations to identify individual ports
participating in a bond.
The LACP port priority of this . In LACP
negotiations s with numerically lower
priorities are preferred for aggregation.
The LACP aggregation key of this . s with different aggregation keys may not be active
within a given at the same time.
These key-value pairs specifically apply to an interface that
represents a virtual Ethernet interface connected to a virtual
machine. These key-value pairs should not be present for other types
of interfaces. Keys whose names end in -uuid
have
values that uniquely identify the entity in question. For a Citrix
XenServer hypervisor, these values are UUIDs in RFC 4122 format.
Other hypervisors may use other formats.
The MAC address programmed into the ``virtual hardware'' for this
interface, in the form
xx:xx:xx:xx:xx:xx.
For Citrix XenServer, this is the value of the MAC
field
in the VIF record for this interface.
A system-unique identifier for the interface. On XenServer, this will
commonly be the same as .
Hypervisors may sometimes have more than one interface associated
with a given , only one of
which is actually in use at a given time. For example, in some
circumstances XenServer has both a ``tap'' and a ``vif'' interface
for a single , but only
uses one of them at a time. A hypervisor that behaves this way must
mark the currently in use interface active
and the
others inactive
. A hypervisor that never has more than
one interface for a given
may mark that interface active
or omit entirely.
During VM migration, a given might transiently be marked active
on
two different hypervisors. That is, active
means that
this is the active
instance within a single hypervisor, not in a broader scope.
The virtual interface associated with this interface.
The virtual network to which this interface is attached.
The VM to which this interface belongs. On XenServer, this will be the
same as .
The VM to which this interface belongs.
The ``VLAN splinters'' feature increases Open vSwitch compatibility
with buggy network drivers in old versions of Linux that do not
properly support VLANs when VLAN devices are not used, at some cost
in memory and performance.
When VLAN splinters are enabled on a particular interface, Open vSwitch
creates a VLAN device for each in-use VLAN. For sending traffic tagged
with a VLAN on the interface, it substitutes the VLAN device. Traffic
received on the VLAN device is treated as if it had been received on
the interface on the particular VLAN.
VLAN splinters consider a VLAN to be in use if:
-
The VLAN is the
value in any record.
-
The VLAN is listed within the
column of the record of an interface on which
VLAN splinters are enabled.
An empty does not influence the
in-use VLANs: creating 4,096 VLAN devices is impractical because it
will exceed the current 1,024 port per datapath limit.
-
An OpenFlow flow within any bridge matches the VLAN.
The same set of in-use VLANs applies to every interface on which VLAN
splinters are enabled. That is, the set is not chosen separately for
each interface but selected once as the union of all in-use VLANs based
on the rules above.
It does not make sense to enable VLAN splinters on an interface for an
access port, or on an interface that is not a physical port.
VLAN splinters are deprecated. When broken device drivers are no
longer in widespread use, we will delete this feature.
Set to true
to enable VLAN splinters on this interface.
Defaults to false
.
VLAN splinters increase kernel and userspace memory overhead, so do
not use them unless they are needed.
VLAN splinters do not support 802.1p priority tags. Received
priorities will appear to be 0, regardless of their actual values,
and priorities on transmitted packets will also be cleared to 0.
The overall purpose of these columns is described under Common
Columns
at the beginning of this document.
Configuration for a particular OpenFlow table.
The table's name. Set this column to change the name that controllers
will receive when they request table statistics, e.g. ovs-ofctl
dump-tables
. The name does not affect switch behavior.
If set, limits the number of flows that may be added to the table. Open
vSwitch may limit the number of flows in a table for other reasons,
e.g. due to hardware limitations or for resource availability or
performance reasons.
Controls the switch's behavior when an OpenFlow flow table modification
request would add flows in excess of . The
supported values are:
refuse
-
Refuse to add the flow or flows. This is also the default policy
when
is unset.
evict
-
Delete the flow that will expire soonest. See
for details.
When is evict
, this
controls how flows are chosen for eviction when the flow table would
otherwise exceed flows. Its value is a set
of NXM fields or sub-fields, each of which takes one of the forms
field[]
or
field[start..end]
,
e.g. NXM_OF_IN_PORT[]
. Please see
nicira-ext.h
for a complete list of NXM field names.
When a flow must be evicted due to overflow, the flow to evict is
chosen through an approximation of the following algorithm:
-
Divide the flows in the table into groups based on the values of the
specified fields or subfields, so that all of the flows in a given
group have the same values for those fields. If a flow does not
specify a given field, that field's value is treated as 0.
-
Consider the flows in the largest group, that is, the group that
contains the greatest number of flows. If two or more groups all
have the same largest number of flows, consider the flows in all of
those groups.
-
Among the flows under consideration, choose the flow that expires
soonest for eviction.
The eviction process only considers flows that have an idle timeout or
a hard timeout. That is, eviction never deletes permanent flows.
(Permanent flows do count against .
Open vSwitch ignores any invalid or unknown field specifications.
When is not evict
, this
column has no effect.
Quality of Service (QoS) configuration for each Port that
references it.
The type of QoS to implement. The currently defined types are
listed below:
linux-htb
-
Linux ``hierarchy token bucket'' classifier. See tc-htb(8) (also at
http://linux.die.net/man/8/tc-htb
) and the HTB manual
(http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm
)
for information on how this classifier works and how to configure it.
linux-hfsc
-
Linux "Hierarchical Fair Service Curve" classifier.
See
http://linux-ip.net/articles/hfsc.en/
for
information on how this classifier works.
A map from queue numbers to records. The
supported range of queue numbers depend on . The
queue numbers are the same as the queue_id
used in
OpenFlow in struct ofp_action_enqueue
and other
structures.
Queue 0 is the ``default queue.'' It is used by OpenFlow output
actions when no specific queue has been set. When no configuration for
queue 0 is present, it is automatically configured as if a record with empty
and columns had been
specified.
(Before version 1.6, Open vSwitch would leave queue 0 unconfigured in
this case. With some queuing disciplines, this dropped all packets
destined for the default queue.)
The linux-htb
and linux-hfsc
classes support
the following key-value pair:
Maximum rate shared by all queued traffic, in bit/s. Optional. If not
specified, for physical interfaces, the default is the link rate. For
other interfaces or if the link rate cannot be determined, the default
is currently 100 Mbps.
The overall purpose of these columns is described under Common
Columns
at the beginning of this document.
A port mirror within a .
A port mirror configures a bridge to send selected frames to special
``mirrored'' ports, in addition to their normal destinations. Mirroring
traffic may also be referred to as SPAN or RSPAN, depending on how
the mirrored traffic is sent.
Arbitrary identifier for the .
To be selected for mirroring, a given packet must enter or leave the
bridge through a selected port and it must also be in one of the
selected VLANs.
If true, every packet arriving or departing on any port is
selected for mirroring.
Ports on which departing packets are selected for mirroring.
Ports on which arriving packets are selected for mirroring.
VLANs on which packets are selected for mirroring. An empty set
selects packets on all VLANs.
These columns are mutually exclusive. Exactly one of them must be
nonempty.
Output port for selected packets, if nonempty.
Specifying a port for mirror output reserves that port exclusively
for mirroring. No frames other than those selected for mirroring
via this column
will be forwarded to the port, and any frames received on the port
will be discarded.
The output port may be any kind of port supported by Open vSwitch.
It may be, for example, a physical port (sometimes called SPAN) or a
GRE tunnel.
Output VLAN for selected packets, if nonempty.
The frames will be sent out all ports that trunk
, as well as any ports with implicit VLAN
. When a mirrored frame is sent out a
trunk port, the frame's VLAN tag will be set to
, replacing any existing tag; when it is
sent out an implicit VLAN port, the frame will not be tagged. This
type of mirroring is sometimes called RSPAN.
The following destination MAC addresses will not be mirrored to a
VLAN to avoid confusing switches that interpret the protocols that
they represent:
01:80:c2:00:00:00
- IEEE 802.1D Spanning Tree Protocol (STP).
01:80:c2:00:00:01
- IEEE Pause frame.
01:80:c2:00:00:0x
- Other reserved protocols.
01:00:0c:cc:cc:cc
-
Cisco Discovery Protocol (CDP), VLAN Trunking Protocol (VTP),
Dynamic Trunking Protocol (DTP), Port Aggregation Protocol (PAgP),
and others.
01:00:0c:cc:cc:cd
- Cisco Shared Spanning Tree Protocol PVSTP+.
01:00:0c:cd:cd:cd
- Cisco STP Uplink Fast.
01:00:0c:00:00:00
- Cisco Inter Switch Link.
Please note: Mirroring to a VLAN can disrupt a network that
contains unmanaged switches. Consider an unmanaged physical switch
with two ports: port 1, connected to an end host, and port 2,
connected to an Open vSwitch configured to mirror received packets
into VLAN 123 on port 2. Suppose that the end host sends a packet on
port 1 that the physical switch forwards to port 2. The Open vSwitch
forwards this packet to its destination and then reflects it back on
port 2 in VLAN 123. This reflected packet causes the unmanaged
physical switch to replace the MAC learning table entry, which
correctly pointed to port 1, with one that incorrectly points to port
2. Afterward, the physical switch will direct packets destined for
the end host to the Open vSwitch on port 2, instead of to the end
host on port 1, disrupting connectivity. If mirroring to a VLAN is
desired in this scenario, then the physical switch must be replaced
by one that learns Ethernet addresses on a per-VLAN basis. In
addition, learning should be disabled on the VLAN containing mirrored
traffic. If this is not done then intermediate switches will learn
the MAC address of each end host from the mirrored traffic. If
packets being sent to that end host are also mirrored, then they will
be dropped since the switch will attempt to send them out the input
port. Disabling learning for the VLAN will cause the switch to
correctly send the packet out all ports configured for that VLAN. If
Open vSwitch is being used as an intermediate switch, learning can be
disabled by adding the mirrored VLAN to
in the appropriate table or tables.
Mirroring to a GRE tunnel has fewer caveats than mirroring to a
VLAN and should generally be preferred.
Key-value pairs that report mirror statistics.
Number of packets transmitted through this mirror.
Number of bytes transmitted through this mirror.
The overall purpose of these columns is described under Common
Columns
at the beginning of this document.
An OpenFlow controller.
Open vSwitch supports two kinds of OpenFlow controllers:
- Primary controllers
-
This is the kind of controller envisioned by the OpenFlow 1.0
specification. Usually, a primary controller implements a network
policy by taking charge of the switch's flow table.
Open vSwitch initiates and maintains persistent connections to
primary controllers, retrying the connection each time it fails or
drops. The column in the
table applies to primary controllers.
Open vSwitch permits a bridge to have any number of primary
controllers. When multiple controllers are configured, Open
vSwitch connects to all of them simultaneously. Because
OpenFlow 1.0 does not specify how multiple controllers
coordinate in interacting with a single switch, more than
one primary controller should be specified only if the
controllers are themselves designed to coordinate with each
other. (The Nicira-defined NXT_ROLE
OpenFlow
vendor extension may be useful for this.)
- Service controllers
-
These kinds of OpenFlow controller connections are intended for
occasional support and maintenance use, e.g. with
ovs-ofctl
. Usually a service controller connects only
briefly to inspect or modify some of a switch's state.
Open vSwitch listens for incoming connections from service
controllers. The service controllers initiate and, if necessary,
maintain the connections from their end. The column in the table does
not apply to service controllers.
Open vSwitch supports configuring any number of service controllers.
The determines the type of controller.
Connection method for controller.
The following connection methods are currently supported for primary
controllers:
ssl:ip
[:port
]
-
The specified SSL port (default: 6633) on the host at
the given ip, which must be expressed as an IP address
(not a DNS name). The
column in the table must point to a
valid SSL configuration when this form is used.
SSL support is an optional feature that is not always built as
part of Open vSwitch.
tcp:ip
[:port
]
- The specified TCP port (default: 6633) on the host at
the given ip, which must be expressed as an IP address
(not a DNS name).
The following connection methods are currently supported for service
controllers:
pssl:
[port][:ip
]
-
Listens for SSL connections on the specified TCP port
(default: 6633). If ip, which must be expressed as an
IP address (not a DNS name), is specified, then connections are
restricted to the specified local IP address.
The column in the table must point to a valid SSL
configuration when this form is used.
SSL support is an optional feature that is not always built as
part of Open vSwitch.
ptcp:
[port][:ip
]
-
Listens for connections on the specified TCP port
(default: 6633). If ip, which must be expressed as an
IP address (not a DNS name), is specified, then connections are
restricted to the specified local IP address.
When multiple controllers are configured for a single bridge, the
values must be unique. Duplicate
values yield unspecified results.
If it is specified, this setting must be one of the following
strings that describes how Open vSwitch contacts this OpenFlow
controller over the network:
in-band
- In this mode, this controller's OpenFlow traffic travels over the
bridge associated with the controller. With this setting, Open
vSwitch allows traffic to and from the controller regardless of the
contents of the OpenFlow flow table. (Otherwise, Open vSwitch
would never be able to connect to the controller, because it did
not have a flow to enable it.) This is the most common connection
mode because it is not necessary to maintain two independent
networks.
out-of-band
- In this mode, OpenFlow traffic uses a control network separate
from the bridge associated with this controller, that is, the
bridge does not use any of its own network devices to communicate
with the controller. The control network must be configured
separately, before or after
ovs-vswitchd
is started.
If not specified, the default is implementation-specific.
Maximum number of milliseconds to wait between connection attempts.
Default is implementation-specific.
Maximum number of milliseconds of idle time on connection to
controller before sending an inactivity probe message. If Open
vSwitch does not communicate with the controller for the specified
number of seconds, it will send a probe. If a response is not
received for the same additional amount of time, Open vSwitch
assumes the connection has been broken and attempts to reconnect.
Default is implementation-specific. A value of 0 disables
inactivity probes.
OpenFlow switches send certain messages to controllers spontanenously,
that is, not in response to any request from the controller. These
messages are called ``asynchronous messages.'' These columns allow
asynchronous messages to be limited or disabled to ensure the best use
of network resources.
The OpenFlow protocol enables asynchronous messages at time of
connection establishment, which means that a controller can receive
asynchronous messages, potentially many of them, even if it turns them
off immediately after connecting. Set this column to
false
to change Open vSwitch behavior to disable, by
default, all asynchronous messages. The controller can use the
NXT_SET_ASYNC_CONFIG
Nicira extension to OpenFlow to turn
on any messages that it does want to receive, if any.
The maximum rate at which the switch will forward packets to the
OpenFlow controller, in packets per second. This feature prevents a
single bridge from overwhelming the controller. If not specified,
the default is implementation-specific.
In addition, when a high rate triggers rate-limiting, Open vSwitch
queues controller packets for each port and transmits them to the
controller at the configured rate. The value limits the number of queued
packets. Ports on a bridge share the packet queue fairly.
Open vSwitch maintains two such packet rate-limiters per bridge: one
for packets sent up to the controller because they do not correspond
to any flow, and the other for packets sent up to the controller by
request through flow actions. When both rate-limiters are filled with
packets, the actual rate that packets are sent to the controller is
up to twice the specified rate.
In conjunction with ,
the maximum number of unused packet credits that the bridge will
allow to accumulate, in packets. If not specified, the default
is implementation-specific.
These values are considered only in in-band control mode (see
).
When multiple controllers are configured on a single bridge, there
should be only one set of unique values in these columns. If different
values are set for these columns in different controllers, the effect
is unspecified.
The IP address to configure on the local port,
e.g. 192.168.0.123
. If this value is unset, then
and are
ignored.
The IP netmask to configure on the local port,
e.g. 255.255.255.0
. If is set
but this value is unset, then the default is chosen based on whether
the IP address is class A, B, or C.
The IP address of the gateway to configure on the local port, as a
string, e.g. 192.168.0.1
. Leave this column unset if
this network has no gateway.
true
if currently connected to this controller,
false
otherwise.
The level of authority this controller has on the associated
bridge. Possible values are:
other
- Allows the controller access to all OpenFlow features.
master
- Equivalent to
other
, except that there may be at
most one master controller at a time. When a controller configures
itself as master
, any existing master is demoted to
the slave
role.
slave
- Allows the controller read-only access to OpenFlow features.
Attempts to modify the flow table will be rejected with an
error. Slave controllers do not receive OFPT_PACKET_IN or
OFPT_FLOW_REMOVED messages, but they do receive OFPT_PORT_STATUS
messages.
A human-readable description of the last error on the connection
to the controller; i.e. strerror(errno)
. This key
will exist only if an error has occurred.
The state of the connection to the controller:
VOID
- Connection is disabled.
BACKOFF
- Attempting to reconnect at an increasing period.
CONNECTING
- Attempting to connect.
ACTIVE
- Connected, remote host responsive.
IDLE
- Connection is idle. Waiting for response to keep-alive.
These values may change in the future. They are provided only for
human consumption.
The amount of time since this controller last successfully connected to
the switch (in seconds). Value is empty if controller has never
successfully connected.
The amount of time since this controller last disconnected from
the switch (in seconds). Value is empty if controller has never
disconnected.
Additional configuration for a connection between the controller
and the Open vSwitch.
The Differentiated Service Code Point (DSCP) is specified using 6 bits
in the Type of Service (TOS) field in the IP header. DSCP provides a
mechanism to classify the network traffic and provide Quality of
Service (QoS) on IP networks.
The DSCP value specified here is used when establishing the connection
between the controller and the Open vSwitch. The connection must be
reset for the new DSCP values to take effect. If no value is
specified, a default value of 48 is chosen. Valid DSCP values must be
in the range 0 to 63.
The overall purpose of these columns is described under Common
Columns
at the beginning of this document.
Configuration for a database connection to an Open vSwitch database
(OVSDB) client.
This table primarily configures the Open vSwitch database
(ovsdb-server
), not the Open vSwitch switch
(ovs-vswitchd
). The switch does read the table to determine
what connections should be treated as in-band.
The Open vSwitch database server can initiate and maintain active
connections to remote clients. It can also listen for database
connections.
Connection method for managers.
The following connection methods are currently supported:
ssl:ip
[:port
]
-
The specified SSL port (default: 6632) on the host at
the given ip, which must be expressed as an IP address
(not a DNS name). The
column in the table must point to a
valid SSL configuration when this form is used.
SSL support is an optional feature that is not always built as
part of Open vSwitch.
tcp:ip
[:port
]
-
The specified TCP port (default: 6632) on the host at
the given ip, which must be expressed as an IP address
(not a DNS name).
pssl:
[port][:ip
]
-
Listens for SSL connections on the specified TCP port
(default: 6632). If ip, which must be expressed as an
IP address (not a DNS name), is specified, then connections are
restricted to the specified local IP address.
The column in the table must point to a valid SSL
configuration when this form is used.
SSL support is an optional feature that is not always built as
part of Open vSwitch.
ptcp:
[port][:ip
]
-
Listens for connections on the specified TCP port
(default: 6632). If ip, which must be expressed as an
IP address (not a DNS name), is specified, then connections are
restricted to the specified local IP address.
When multiple managers are configured, the
values must be unique. Duplicate values yield
unspecified results.
If it is specified, this setting must be one of the following strings
that describes how Open vSwitch contacts this OVSDB client over the
network:
in-band
-
In this mode, this connection's traffic travels over a bridge
managed by Open vSwitch. With this setting, Open vSwitch allows
traffic to and from the client regardless of the contents of the
OpenFlow flow table. (Otherwise, Open vSwitch would never be able
to connect to the client, because it did not have a flow to enable
it.) This is the most common connection mode because it is not
necessary to maintain two independent networks.
out-of-band
-
In this mode, the client's traffic uses a control network separate
from that managed by Open vSwitch, that is, Open vSwitch does not
use any of its own network devices to communicate with the client.
The control network must be configured separately, before or after
ovs-vswitchd
is started.
If not specified, the default is implementation-specific.
Maximum number of milliseconds to wait between connection attempts.
Default is implementation-specific.
Maximum number of milliseconds of idle time on connection to the client
before sending an inactivity probe message. If Open vSwitch does not
communicate with the client for the specified number of seconds, it
will send a probe. If a response is not received for the same
additional amount of time, Open vSwitch assumes the connection has been
broken and attempts to reconnect. Default is implementation-specific.
A value of 0 disables inactivity probes.
true
if currently connected to this manager,
false
otherwise.
A human-readable description of the last error on the connection
to the manager; i.e. strerror(errno)
. This key
will exist only if an error has occurred.
The state of the connection to the manager:
VOID
- Connection is disabled.
BACKOFF
- Attempting to reconnect at an increasing period.
CONNECTING
- Attempting to connect.
ACTIVE
- Connected, remote host responsive.
IDLE
- Connection is idle. Waiting for response to keep-alive.
These values may change in the future. They are provided only for
human consumption.
The amount of time since this manager last successfully connected
to the database (in seconds). Value is empty if manager has never
successfully connected.
The amount of time since this manager last disconnected from the
database (in seconds). Value is empty if manager has never
disconnected.
Space-separated list of the names of OVSDB locks that the connection
holds. Omitted if the connection does not hold any locks.
Space-separated list of the names of OVSDB locks that the connection is
currently waiting to acquire. Omitted if the connection is not waiting
for any locks.
Space-separated list of the names of OVSDB locks that the connection
has had stolen by another OVSDB client. Omitted if no locks have been
stolen from this connection.
When specifies a connection method that
listens for inbound connections (e.g. ptcp:
or
pssl:
) and more than one connection is actually active,
the value is the number of active connections. Otherwise, this
key-value pair is omitted.
When multiple connections are active, status columns and key-value
pairs (other than this one) report the status of one arbitrarily
chosen connection.
Additional configuration for a connection between the manager
and the Open vSwitch Database.
The Differentiated Service Code Point (DSCP) is specified using 6 bits
in the Type of Service (TOS) field in the IP header. DSCP provides a
mechanism to classify the network traffic and provide Quality of
Service (QoS) on IP networks.
The DSCP value specified here is used when establishing the connection
between the manager and the Open vSwitch. The connection must be
reset for the new DSCP values to take effect. If no value is
specified, a default value of 48 is chosen. Valid DSCP values must be
in the range 0 to 63.
The overall purpose of these columns is described under Common
Columns
at the beginning of this document.