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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | RUNTIME MANAGEMENT COMMANDS | OPENFLOW IMPLEMENTATION | LIMITS | SEE ALSO | COLOPHON |
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ovs-vswitchd(8) Open vSwitch Manual ovs-vswitchd(8)
ovs-vswitchd - Open vSwitch daemon
ovs-vswitchd [database]
A daemon that manages and controls any number of Open vSwitch
switches on the local machine.
The database argument specifies how ovs-vswitchd connects to
ovsdb-server. database may be an OVSDB active or passive
connection method, as described in ovsdb(7). The default is
unix:/usr/local/var/run/openvswitch/db.sock.
ovs-vswitchd retrieves its configuration from database at startup.
It sets up Open vSwitch datapaths and then operates switching
across each bridge described in its configuration files. As the
database changes, ovs-vswitchd automatically updates its
configuration to match.
ovs-vswitchd switches may be configured with any of the following
features:
• L2 switching with MAC learning.
• NIC bonding with automatic fail-over and source MAC-based
TX load balancing ("SLB").
• 802.1Q VLAN support.
• Port mirroring, with optional VLAN tagging.
• NetFlow v5 flow logging.
• sFlow(R) monitoring.
• Connectivity to an external OpenFlow controller, such as
NOX.
Only a single instance of ovs-vswitchd is intended to run at a
time. A single ovs-vswitchd can manage any number of switch
instances, up to the maximum number of supported Open vSwitch
datapaths.
ovs-vswitchd does all the necessary management of Open vSwitch
datapaths itself. Thus, ovs-dpctl(8) (and its userspace datapath
counterparts accessible via ovs-appctl dpctl/command) are not
needed with ovs-vswitchd and should not be used because they can
interfere with its operation. These tools are still useful for
diagnostics.
An Open vSwitch datapath kernel module must be loaded for
ovs-vswitchd to be useful. Refer to the documentation for
instructions on how to build and load the Open vSwitch kernel
module.
--mlockall
Causes ovs-vswitchd to call the mlockall() function, to
attempt to lock all of its process memory into physical RAM
on page faults (on allocation, when running on Linux kernel
4.4 or older), preventing the kernel from paging any of its
memory to disk. This helps to avoid networking
interruptions due to system memory pressure.
Some systems do not support mlockall() at all, and other
systems only allow privileged users, such as the superuser,
to use it. ovs-vswitchd emits a log message if mlockall()
is unavailable or unsuccessful.
DPDK Options
For details on initializing ovs-vswitchd to use DPDK ports, refer
to the documentation or ovs-vswitchd.conf.db(5).
DPDK HW Access Options
--hw-rawio-access
Tells ovs-vswitchd to retain the CAP_SYS_RAWIO capability,
to allow userspace drivers access to raw hardware memory.
This will also allow the ovs-vswitchd daemon to call iopl()
and ioperm() functions as well as access memory devices to
set port access. This is a very powerful capability, so
generally only enable as needed for specific hardware (for
example mlx5 with full hardware offload via rte_flow).
Daemon Options
The following options are valid on POSIX based platforms.
--pidfile[=pidfile]
Causes a file (by default, ovs-vswitchd.pid) to be created
indicating the PID of the running process. If the pidfile
argument is not specified, or if it does not begin with /,
then it is created in /usr/local/var/run/openvswitch.
If --pidfile is not specified, no pidfile is created.
--overwrite-pidfile
By default, when --pidfile is specified and the specified
pidfile already exists and is locked by a running process,
ovs-vswitchd refuses to start. Specify --overwrite-pidfile
to cause it to instead overwrite the pidfile.
When --pidfile is not specified, this option has no effect.
--detach
Runs ovs-vswitchd as a background process. The process
forks, and in the child it starts a new session, closes the
standard file descriptors (which has the side effect of
disabling logging to the console), and changes its current
directory to the root (unless --no-chdir is specified).
After the child completes its initialization, the parent
exits. ovs-vswitchd detaches only after it has connected
to the database, retrieved the initial configuration, and
set up that configuration.
--monitor
Creates an additional process to monitor the ovs-vswitchd
daemon. If the daemon dies due to a signal that indicates
a programming error (SIGABRT, SIGALRM, SIGBUS, SIGFPE,
SIGILL, SIGPIPE, SIGSEGV, SIGXCPU, or SIGXFSZ) then the
monitor process starts a new copy of it. If the daemon
dies or exits for another reason, the monitor process
exits.
This option is normally used with --detach, but it also
functions without it.
--no-chdir
By default, when --detach is specified, ovs-vswitchd
changes its current working directory to the root directory
after it detaches. Otherwise, invoking ovs-vswitchd from a
carelessly chosen directory would prevent the administrator
from unmounting the file system that holds that directory.
Specifying --no-chdir suppresses this behavior, preventing
ovs-vswitchd from changing its current working directory.
This may be useful for collecting core files, since it is
common behavior to write core dumps into the current
working directory and the root directory is not a good
directory to use.
This option has no effect when --detach is not specified.
--no-self-confinement
By default daemon will try to self-confine itself to work
with files under well-known directories determined during
build. It is better to stick with this default behavior
and not to use this flag unless some other Access Control
is used to confine daemon. Note that in contrast to other
access control implementations that are typically enforced
from kernel-space (e.g. DAC or MAC), self-confinement is
imposed from the user-space daemon itself and hence should
not be considered as a full confinement strategy, but
instead should be viewed as an additional layer of
security.
--user Causes ovs-vswitchd to run as a different user specified in
"user:group", thus dropping most of the root privileges.
Short forms "user" and ":group" are also allowed, with
current user or group are assumed respectively. Only
daemons started by the root user accepts this argument.
On Linux, daemons will be granted CAP_IPC_LOCK and
CAP_NET_BIND_SERVICES before dropping root privileges.
Daemons that interact with a datapath, such as
ovs-vswitchd, will be granted three additional
capabilities, namely CAP_NET_ADMIN, CAP_NET_BROADCAST and
CAP_NET_RAW. The capability change will apply even if the
new user is root.
On Windows, this option is not currently supported. For
security reasons, specifying this option will cause the
daemon process not to start.
Service Options
The following options are valid only on Windows platform.
--service
Causes ovs-vswitchd to run as a service in the background.
The service should already have been created through
external tools like SC.exe.
--service-monitor
Causes the ovs-vswitchd service to be automatically
restarted by the Windows services manager if the service
dies or exits for unexpected reasons.
When --service is not specified, this option has no effect.
Public Key Infrastructure Options
-p privkey.pem
--private-key=privkey.pem
Specifies a PEM file containing the private key used as
ovs-vswitchd's identity for outgoing SSL/TLS connections.
-c cert.pem
--certificate=cert.pem
Specifies a PEM file containing a certificate that
certifies the private key specified on -p or --private-key
to be trustworthy. The certificate must be signed by the
certificate authority (CA) that the peer in SSL/TLS
connections will use to verify it.
-C cacert.pem
--ca-cert=cacert.pem
Specifies a PEM file containing the CA certificate that
ovs-vswitchd should use to verify certificates presented to
it by SSL/TLS peers. (This may be the same certificate
that SSL/TLS peers use to verify the certificate specified
on -c or --certificate, or it may be a different one,
depending on the PKI design in use.)
-C none
--ca-cert=none
Disables verification of certificates presented by SSL/TLS
peers. This introduces a security risk, because it means
that certificates cannot be verified to be those of known
trusted hosts.
--bootstrap-ca-cert=cacert.pem
When cacert.pem exists, this option has the same effect as
-C or --ca-cert. If it does not exist, then ovs-vswitchd
will attempt to obtain the CA certificate from the SSL/TLS
peer on its first SSL/TLS connection and save it to the
named PEM file. If it is successful, it will immediately
drop the connection and reconnect, and from then on all
SSL/TLS connections must be authenticated by a certificate
signed by the CA certificate thus obtained.
This option exposes the SSL/TLS connection to a man-in-the-
middle attack obtaining the initial CA certificate, but it
may be useful for bootstrapping.
This option is only useful if the SSL/TLS peer sends its CA
certificate as part of the SSL/TLS certificate chain.
SSL/TLS protocols do not require the server to send the CA
certificate.
This option is mutually exclusive with -C and --ca-cert.
--peer-ca-cert=peer-cacert.pem
Specifies a PEM file that contains one or more additional
certificates to send to SSL/TLS peers. peer-cacert.pem
should be the CA certificate used to sign ovs-vswitchd's
own certificate, that is, the certificate specified on -c
or --certificate. If ovs-vswitchd's certificate is self-
signed, then --certificate and --peer-ca-cert should
specify the same file.
This option is not useful in normal operation, because the
SSL/TLS peer must already have the CA certificate for the
peer to have any confidence in ovs-vswitchd's identity.
However, this offers a way for a new installation to
bootstrap the CA certificate on its first SSL/TLS
connection.
Logging Options
-v[spec]
--verbose=[spec]
Sets logging levels. Without any spec, sets the log level
for every module and destination to dbg. Otherwise, spec
is a list of words separated by spaces or commas or colons,
up to one from each category below:
• A valid module name, as displayed by the vlog/list
command on ovs-appctl(8), limits the log level
change to the specified module.
• syslog, console, or file, to limit the log level
change to only to the system log, to the console, or
to a file, respectively. (If --detach is specified,
ovs-vswitchd closes its standard file descriptors,
so logging to the console will have no effect.)
On Windows platform, syslog is accepted as a word
and is only useful along with the --syslog-target
option (the word has no effect otherwise).
• off, emer, err, warn, info, or dbg, to control the
log level. Messages of the given severity or higher
will be logged, and messages of lower severity will
be filtered out. off filters out all messages. See
ovs-appctl(8) for a definition of each log level.
Case is not significant within spec.
Regardless of the log levels set for file, logging to a
file will not take place unless --log-file is also
specified (see below).
For compatibility with older versions of OVS, any is
accepted as a word but has no effect.
-v
--verbose
Sets the maximum logging verbosity level, equivalent to
--verbose=dbg.
-vPATTERN:destination:pattern
--verbose=PATTERN:destination:pattern
Sets the log pattern for destination to pattern. Refer to
ovs-appctl(8) for a description of the valid syntax for
pattern.
-vFACILITY:facility
--verbose=FACILITY:facility
Sets the RFC5424 facility of the log message. facility can
be one of kern, user, mail, daemon, auth, syslog, lpr,
news, uucp, clock, ftp, ntp, audit, alert, clock2, local0,
local1, local2, local3, local4, local5, local6 or local7.
If this option is not specified, daemon is used as the
default for the local system syslog and local0 is used
while sending a message to the target provided via the
--syslog-target option.
--log-file[=file]
Enables logging to a file. If file is specified, then it
is used as the exact name for the log file. The default
log file name used if file is omitted is
/usr/local/var/log/openvswitch/ovs-vswitchd.log.
--syslog-target=host:port
Send syslog messages to UDP port on host, in addition to
the system syslog. The host must be a numerical IP
address, not a hostname.
--syslog-method=method
Specify method how syslog messages should be sent to syslog
daemon. Following forms are supported:
• libc, use libc syslog() function. Downside of using
this options is that libc adds fixed prefix to every
message before it is actually sent to the syslog
daemon over /dev/log UNIX domain socket.
• unix:file, use UNIX domain socket directly. It is
possible to specify arbitrary message format with
this option. However, rsyslogd 8.9 and older
versions use hard coded parser function anyway that
limits UNIX domain socket use. If you want to use
arbitrary message format with older rsyslogd
versions, then use UDP socket to localhost IP
address instead.
• udp:ip:port, use UDP socket. With this method it is
possible to use arbitrary message format also with
older rsyslogd. When sending syslog messages over
UDP socket extra precaution needs to be taken into
account, for example, syslog daemon needs to be
configured to listen on the specified UDP port,
accidental iptables rules could be interfering with
local syslog traffic and there are some security
considerations that apply to UDP sockets, but do not
apply to UNIX domain sockets.
• null, discards all messages logged to syslog.
The default is taken from the OVS_SYSLOG_METHOD environment
variable; if it is unset, the default is libc.
Other Options
--unixctl=socket
Sets the name of the control socket on which ovs-vswitchd
listens for runtime management commands (see RUNTIME
MANAGEMENT COMMANDS, below). If socket does not begin with
/, it is interpreted as relative to
/usr/local/var/run/openvswitch. If --unixctl is not used
at all, the default socket is
/usr/local/var/run/openvswitch/ovs-vswitchd.pid.ctl, where
pid is ovs-vswitchd's process ID.
On Windows a local named pipe is used to listen for runtime
management commands. A file is created in the absolute
path as pointed by socket or if --unixctl is not used at
all, a file is created as ovs-vswitchd.ctl in the
configured OVS_RUNDIR directory. The file exists just to
mimic the behavior of a Unix domain socket.
Specifying none for socket disables the control socket
feature.
-h
--help Prints a brief help message to the console.
-V
--version
Prints version information to the console.
ovs-appctl(8) can send commands to a running ovs-vswitchd process.
The currently supported commands are described below. The command
descriptions assume an understanding of how to configure Open
vSwitch.
GENERAL COMMANDS
exit --cleanup
Causes ovs-vswitchd to gracefully terminate. If --cleanup
is specified, deletes flows from datapaths and releases
other datapath resources configured by ovs-vswitchd.
Otherwise, datapath flows and other resources remains
undeleted. Resources of datapaths that are integrated into
ovs-vswitchd (e.g. the netdev datapath type) are always
released regardless of --cleanup except for ports with
internal type. Use --cleanup to release internal ports too.
qos/show-types interface
Queries the interface for a list of Quality of Service
types that are configurable via Open vSwitch for the given
interface.
qos/show interface
Queries the kernel for Quality of Service configuration and
statistics associated with the given interface.
bfd/show [interface]
Displays detailed information about Bidirectional
Forwarding Detection configured on interface. If interface
is not specified, then displays detailed information about
all interfaces with BFD enabled.
bfd/set-forwarding [interface] status
Force the fault status of the BFD module on interface (or
all interfaces if none is given) to be status. status can
be "true", "false", or "normal" which reverts to the
standard behavior.
cfm/show [interface]
Displays detailed information about Connectivity Fault
Management configured on interface. If interface is not
specified, then displays detailed information about all
interfaces with CFM enabled.
cfm/set-fault [interface] status
Force the fault status of the CFM module on interface (or
all interfaces if none is given) to be status. status can
be "true", "false", or "normal" which reverts to the
standard behavior.
stp/tcn [bridge]
Forces a topology change event on bridge if it's running
STP. This may cause it to send Topology Change
Notifications to its peers and flush its MAC table. If no
bridge is given, forces a topology change event on all
bridges.
stp/show [bridge]
Displays detailed information about spanning tree on the
bridge. If bridge is not specified, then displays detailed
information about all bridges with STP enabled.
rstp/tcn [bridge]
Forces a topology change event on bridge if it's running
RSTP. This may cause it to send Topology Change
Notifications to its peers and flush its MAC table. If no
bridge is given, forces a topology change event on all
bridges.
rstp/show [bridge]
Displays detailed information about rapid spanning tree on
the bridge. If bridge is not specified, then displays
detailed information about all bridges with RSTP enabled.
BRIDGE COMMANDS
These commands manage bridges.
fdb/add bridge port vlan mac
Adds mac address to a port and vlan on a bridge. This
utility can be used to pre-populate fdb table without
relying on dynamic mac learning.
fdb/del bridge vlan mac
Deletes mac address from a port and vlan on a bridge.
fdb/flush [bridge]
Flushes bridge MAC address learning table, or all learning
tables if no bridge is given.
fdb/show bridge
Lists each MAC address/VLAN pair learned by the specified
bridge, along with the port on which it was learned and the
age of the entry, in seconds.
fdb/stats-clear [bridge]
Clear bridge MAC address learning table statistics, or all
statistics if no bridge is given.
fdb/stats-show bridge
Show MAC address learning table statistics for the
specified bridge.
mdb/flush [bridge]
Flushes bridge multicast snooping table, or all snooping
tables if no bridge is given.
mdb/show bridge
Lists each multicast group/VLAN pair learned by the
specified bridge, along with the port on which it was
learned and the age of the entry, in seconds.
bridge/reconnect [bridge]
Makes bridge drop all of its OpenFlow controller
connections and reconnect. If bridge is not specified,
then all bridges drop their controller connections and
reconnect.
This command might be useful for debugging OpenFlow
controller issues.
bridge/dump-flows [--offload-stats] bridge
Lists all flows in bridge, including those normally hidden
to commands such as ovs-ofctl dump-flows. Flows set up by
mechanisms such as in-band control and fail-open are hidden
from the controller since it is not allowed to modify or
override them. If --offload-stats are specified then also
list statistics for offloaded packets and bytes, which are
a subset of the total packets and bytes.
BOND COMMANDS
These commands manage bonded ports on an Open vSwitch's bridges.
To understand some of these commands, it is important to
understand a detail of the bonding implementation called ``source
load balancing'' (SLB). Instead of directly assigning Ethernet
source addresses to members, the bonding implementation computes a
function that maps an 48-bit Ethernet source addresses into an
8-bit value (a ``MAC hash'' value). All of the Ethernet addresses
that map to a single 8-bit value are then assigned to a single
member.
bond/list
Lists all of the bonds, and their members, on each bridge.
bond/show [port]
Lists all of the bond-specific information (updelay,
downdelay, time until the next rebalance) about the given
bonded port, or all bonded ports if no port is given. Also
lists information about each members: whether it is enabled
or disabled, the time to completion of an updelay or
downdelay if one is in progress, whether it is the active
member, the hashes assigned to the member. Any LACP
information related to this bond may be found using the
lacp/show command.
bond/migrate port hash member
Only valid for SLB bonds. Assigns a given MAC hash to a
new member. port specifies the bond port, hash the MAC
hash to be migrated (as a decimal number between 0 and
255), and member the new member to be assigned.
The reassignment is not permanent: rebalancing or fail-over
will cause the MAC hash to be shifted to a new member in
the usual manner.
A MAC hash cannot be migrated to a disabled member.
bond/set-active-member port member
Sets member as the active member on port. member must
currently be enabled.
The setting is not permanent: a new active member will be
selected if member becomes disabled.
bond/enable-member port member
bond/disable-member port member
Enables (or disables) member on the given bond port,
skipping any updelay (or downdelay).
This setting is not permanent: it persists only until the
carrier status of member changes.
bond/hash mac [vlan] [basis]
Returns the hash value which would be used for mac with
vlan and basis if specified.
lacp/show [port]
Lists all of the LACP related information about the given
port: active or passive, aggregation key, system id, and
system priority. Also lists information about each member:
whether it is enabled or disabled, whether it is attached
or detached, port id and priority, actor information, and
partner information. If port is not specified, then
displays detailed information about all interfaces with CFM
enabled.
lacp/stats-show [port]
Lists various stats about LACP PDUs (number of RX/TX PDUs,
bad PDUs received) and member state (number of times its
state expired/defaulted and carrier status changed) for the
given port. If port is not specified, then displays stats
of all interfaces with LACP enabled.
DPCTL DATAPATH DEBUGGING COMMANDS
The primary way to configure ovs-vswitchd is through the Open
vSwitch database, e.g. using ovs-vsctl(8). These commands provide
a debugging interface for managing datapaths. They implement the
same features (and syntax) as ovs-dpctl(8). Unlike ovs-dpctl(8),
these commands work with datapaths that are integrated into
ovs-vswitchd (e.g. the netdev datapath type).
Do not use commands to add or remove or modify datapaths if
ovs-vswitchd is running because this interferes with
ovs-vswitchd's own datapath management.
dpctl/add-dp dp [netdev[,option]...]
Creates datapath dp, with a local port also named dp. This
will fail if a network device dp already exists.
If netdevs are specified, ovs-vswitchd adds them to the new
datapath, just as if add-if was specified.
dpctl/del-dp dp
Deletes datapath dp. If dp is associated with any network
devices, they are automatically removed.
dpctl/add-if dp netdev[,option]...
Adds each netdev to the set of network devices datapath dp
monitors, where dp is the name of an existing datapath, and
netdev is the name of one of the host's network devices,
e.g. eth0. Once a network device has been added to a
datapath, the datapath has complete ownership of the
network device's traffic and the network device appears
silent to the rest of the system.
A netdev may be followed by a comma-separated list of
options. The following options are currently supported:
type=type
Specifies the type of port to add. The default type
is system.
port_no=port
Requests a specific port number within the datapath.
If this option is not specified then one will be
automatically assigned.
key=value
Adds an arbitrary key-value option to the port's
configuration.
ovs-vswitchd.conf.db(5) documents the available port types
and options.
dpctl/set-if dp port[,option]...
Reconfigures each port in dp as specified. An option of
the form key=value adds the specified key-value option to
the port or overrides an existing key's value. An option
of the form key=, that is, without a value, deletes the
key-value named key. The type and port number of a port
cannot be changed, so type and port_no are only allowed if
they match the existing configuration.
dpctl/del-if dp netdev...
Removes each netdev from the list of network devices
datapath dp monitors.
dpctl/dump-dps
Prints the name of each configured datapath on a separate
line.
dpctl/show [-s | --statistics] [dp...]
Prints a summary of configured datapaths, including their
datapath numbers and a list of ports connected to each
datapath. (The local port is identified as port 0.) If -s
or --statistics is specified, then packet and byte counters
are also printed for each port.
The datapath numbers consists of flow stats and mega flow
mask stats.
The "lookups" row displays three stats related to flow
lookup triggered by processing incoming packets in the
datapath. "hit" displays number of packets matches existing
flows. "missed" displays the number of packets not matching
any existing flow and require user space processing.
"lost" displays number of packets destined for user space
process but subsequently dropped before reaching userspace.
The sum of "hit" and "miss" equals to the total number of
packets datapath processed.
The "flows" row displays the number of flows in datapath.
The "masks" row displays the mega flow mask stats. This row
is omitted for datapath not implementing mega flow. "hit"
displays the total number of masks visited for matching
incoming packets. "total" displays number of masks in the
datapath. "hit/pkt" displays the average number of masks
visited per packet; the ratio between "hit" and total
number of packets processed by the datapath.
If one or more datapaths are specified, information on only
those datapaths are displayed. Otherwise, ovs-vswitchd
displays information about all configured datapaths.
DATAPATH FLOW TABLE DEBUGGING COMMANDS
The following commands are primarily useful for debugging Open
vSwitch. The flow table entries (both matches and actions) that
they work with are not OpenFlow flow entries. Instead, they are
different and considerably simpler flows maintained by the Open
vSwitch kernel module. Do not use commands to add or remove or
modify datapath flows if ovs-vswitchd is running because it
interferes with ovs-vswitchd's own datapath flow management. Use
ovs-ofctl(8), instead, to work with OpenFlow flow entries.
The dp argument to each of these commands is optional when exactly
one datapath exists, in which case that datapath is the default.
When multiple datapaths exist, then a datapath name is required.
dpctl/dump-flows [-m | --more] [--names | --no-names] [dp]
[filter=filter] [type=type] [pmd=pmd]
Prints to the console all flow entries in datapath dp's
flow table. Without -m or --more, output omits match
fields that a flow wildcards entirely; with -m or --more,
output includes all wildcarded fields.
If filter=filter is specified, only displays the flows that
match the filter. filter is a flow in the form similar to
that accepted by ovs-ofctl(8)'s add-flow command. (This is
not an OpenFlow flow: besides other differences, it never
contains wildcards.) The filter is also useful to match
wildcarded fields in the datapath flow. As an example,
filter='tcp,tp_src=100' will match the datapath flow
containing 'tcp(src=80/0xff00,dst=8080/0xff)'.
If pmd=pmd is specified, only displays flows of the
specified pmd. Using pmd=-1 will restrict the dump to
flows from the main thread. This option is only supported
by the userspace datapath.
If type=type is specified, only displays flows of the
specified types. This option supported only for ovs-appctl
dpctl/dump-flows. type is a comma separated list, which
can contain any of the following:
ovs - displays flows handled in the ovs dp
tc - displays flows handled in the tc dp
dpdk - displays flows fully offloaded by dpdk
offloaded - displays flows offloaded to the HW
non-offloaded - displays flows not offloaded to the HW
partially-offloaded - displays flows where only part of
their proccessing is done in HW
all - displays all the types of flows
By default all the types of flows are displayed. ovs-dpctl
always acts as if the type was ovs.
dpctl/add-flow [dp] flow actions
dpctl/mod-flow [--clear] [--may-create] [-s | --statistics] [dp]
flow actions
Adds or modifies a flow in dp's flow table that, when a
packet matching flow arrives, causes actions to be
executed.
The add-flow command succeeds only if flow does not already
exist in dp. Contrariwise, mod-flow without --may-create
only modifies the actions for an existing flow. With
--may-create, mod-flow will add a new flow or modify an
existing one.
If -s or --statistics is specified, then mod-flow prints
the modified flow's statistics. A flow's statistics are
the number of packets and bytes that have passed through
the flow, the elapsed time since the flow last processed a
packet (if ever), and (for TCP flows) the union of the TCP
flags processed through the flow.
With --clear, mod-flow zeros out the flow's statistics.
The statistics printed if -s or --statistics is also
specified are those from just before clearing the
statistics.
NOTE: flow and actions do not match the syntax used with
ovs-ofctl(8)'s add-flow command.
Usage Examples
Forward ARP between ports 1 and 2 on datapath myDP:
ovs-dpctl add-flow myDP \
"in_port(1),eth(),eth_type(0x0806),arp()" 2
ovs-dpctl add-flow myDP \
"in_port(2),eth(),eth_type(0x0806),arp()" 1
Forward all IPv4 traffic between two addresses on ports 1
and 2:
ovs-dpctl add-flow myDP \
"in_port(1),eth(),eth_type(0x800),\
ipv4(src=172.31.110.4,dst=172.31.110.5)" 2
ovs-dpctl add-flow myDP \
"in_port(2),eth(),eth_type(0x800),\
ipv4(src=172.31.110.5,dst=172.31.110.4)" 1
dpctl/add-flows [dp] file
dpctl/mod-flows [dp] file
dpctl/del-flows [dp] file
Reads flow entries from file (or stdin if file is -) and
adds, modifies, or deletes each entry to the datapath.
Each flow specification (e.g., each line in file) may start
with add, modify, or delete keyword to specify whether a
flow is to be added, modified, or deleted. A flow
specification without one of these keywords is treated
based on the used command. All flow modifications are
executed as individual transactions in the order specified.
dpctl/del-flow [-s | --statistics] [dp] flow
Deletes the flow from dp's flow table that matches flow.
If -s or --statistics is specified, then del-flow prints
the deleted flow's statistics.
dpctl/get-flow [dp] ufid:ufid [-m | --more] [--names | --no-names]
Fetches the flow from dp's flow table with unique
identifier ufid. ufid must be specified as a string of 32
hexadecimal characters.
dpctl/del-flows [dp]
Deletes all flow entries from datapath dp's flow table.
DATAPATH FLOW CACHE COMMANDS
The following commands are useful for debugging and configuring
the datapath flow cache settings.
dpctl/cache-get-size [dp]
Prints the current cache sizes to the console.
dpctl/cache-set-size dp cache size
Set the dp's specific cache to the given size. The cache
name can be found by using the cache-get-size command.
CONNECTION TRACKING TABLE COMMANDS
The following commands are useful for debugging and configuring
the connection tracking table in the datapath.
The dp argument to each of these commands is optional when exactly
one datapath exists, in which case that datapath is the default.
When multiple datapaths exist, then a datapath name is required.
N.B.(Linux specific): the system datapaths (i.e. the Linux kernel
module Open vSwitch datapaths) share a single connection tracking
table (which is also used by other kernel subsystems, such as
iptables, nftables and the regular host stack). Therefore, the
following commands do not apply specifically to one datapath.
dpctl/ipf-set-enabled [dp] v4|v6
dpctl/ipf-set-disabled [dp] v4|v6
Enables or disables IP fragmentation handling for the
userspace connection tracker. Either v4 or v6 must be
specified. Both IPv4 and IPv6 fragment reassembly are
enabled by default. Only supported for the userspace
datapath.
dpctl/ipf-set-min-frag [dp] v4|v6 minfrag
Sets the minimum fragment size (L3 header and data) for
non-final fragments to minfrag. Either v4 or v6 must be
specified. For enhanced DOS security, higher minimum
fragment sizes can usually be used. The default IPv4 value
is 1200 and the clamped minimum is 400. The default IPv6
value is 1280, with a clamped minimum of 400, for testing
flexibility. The maximum fragment size is not clamped,
however, setting this value too high might result in valid
fragments being dropped. Only supported for userspace
datapath.
dpctl/ipf-set-max-nfrags [dp] maxfrags
Sets the maximum number of fragments tracked by the
userspace datapath connection tracker to maxfrags. The
default value is 1000 and the clamped maximum is 5000.
Note that packet buffers can be held by the fragmentation
module while fragments are incomplete, but will timeout
after 15 seconds. Memory pool sizing should be set
accordingly when fragmentation is enabled. Only supported
for userspace datapath.
dpctl/ipf-get-status [dp] [-m | --more]
Gets the configuration settings and fragment counters
associated with the fragmentation handling of the userspace
datapath connection tracker. With -m or --more, also dumps
the IP fragment lists. Only supported for userspace
datapath.
dpctl/dump-conntrack [-m | --more] [-s | --statistics] [dp]
[zone=zone]
Prints to the console all the connection entries in the
tracker used by dp. If zone=zone is specified, only shows
the connections in zone. With --more, some implementation
specific details are included. With --statistics timeouts
and timestamps are added to the output.
dpctl/dump-conntrack-exp [dp] [zone=zone]
Prints to the console all the expectation entries in the
tracker used by dp. If zone=zone is specified, only shows
the expectations in zone. Only supported for userspace
datapath.
dpctl/flush-conntrack [dp] [zone=zone] [ct-origin-tuple [ct-reply-
tuple]]
Flushes the connection entries in the tracker used by dp
based on zone and connection tracking tuple ct-origin-
tuple. If ct-tuple is not provided, flushes all the
connection entries. If zone=zone is specified, only
flushes the connections in zone.
If ct-[orig|reply]-tuple is provided, flushes the
connection entry specified by ct-[orig|reply]-tuple in
zone. The zone defaults to 0 if it is not provided. The
userspace connection tracker requires flushing with the
original pre-NATed tuple and a warning log will be
otherwise generated. The tuple can be partial and will
remove all connections that are matching on the specified
fields. In order to specify only ct-reply-tuple, provide
empty string as ct-origin-tuple.
Note: Currently there is a limitation for matching on ICMP,
in order to partially match on ICMP parameters the
ct-[orig|reply]-tuple has to include either source or
destination IP.
An example of an IPv4 ICMP ct-[orig|reply]-tuple:
"ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=1,icmp_type=8,icmp_code=0,icmp_id=10"
An example of an IPv6 TCP ct-[orig|reply]-tuple:
"ct_ipv6_src=fc00::1,ct_ipv6_dst=fc00::2,ct_nw_proto=6,ct_tp_src=1,ct_tp_dst=2"
dpctl/ct-stats-show [dp] [zone=zone] [-m | --more]
Displays the number of connections grouped by protocol used
by dp. If zone=zone is specified, numbers refer to the
connections in zone. With --more, groups by connection
state for each protocol.
dpctl/ct-bkts [dp] [gt=threshold]
For each conntrack bucket, displays the number of
connections used by dp. If gt=threshold is specified,
bucket numbers are displayed when the number of connections
in a bucket is greater than threshold.
dpctl/ct-set-maxconns [dp] maxconns
Sets the maximum limit of connection tracker entries to
maxconns on dp. This can be used to reduce the processing
load on the system due to connection tracking or simply
limiting connection tracking. If the number of connections
is already over the new maximum limit request then the new
maximum limit will be enforced when the number of
connections decreases to that limit, which normally happens
due to connection expiry. Only supported for userspace
datapath.
dpctl/ct-get-maxconns [dp]
Prints the maximum limit of connection tracker entries on
dp. Only supported for userspace datapath.
dpctl/ct-get-nconns [dp]
Prints the current number of connection tracker entries on
dp. Only supported for userspace datapath.
dpctl/ct-enable-tcp-seq-chk [dp]
dpctl/ct-disable-tcp-seq-chk [dp]
Enables or disables TCP sequence checking. When set to
disabled, all sequence number verification is disabled,
including for TCP resets. This is similar, but not the
same as 'be_liberal' mode, as in Netfilter. Disabling
sequence number verification is not an optimization in
itself, but is needed for some hardware offload support
which might offer some performance advantage. Sequence
number checking is enabled by default to enforce better
security and should only be disabled if required for
hardware offload support. This command is only supported
for the userspace datapath.
dpctl/ct-get-tcp-seq-chk [dp]
Prints whether TCP sequence checking is enabled or disabled
on dp. Only supported for the userspace datapath.
dpctl/ct-set-sweep-interval [dp] ms
Sets the sweep interval. Only supported for the userspace
datapath.
dpctl/ct-get-sweep-interval [dp]
Prints the current sweep interval in ms. Only supported for
the userspace datapath.
dpctl/ct-set-limits [dp] [default=default_limit]
[zone=zone,limit=limit]...
Sets the maximum allowed number of connections in a
connection tracking zone. A specific zone may be set to
limit, and multiple zones may be specified with a comma-
separated list. If a per-zone limit for a particular zone
is not specified in the datapath, it defaults to the
default per-zone limit. A default zone may be specified
with the default=default_limit argument. Initially, the
default per-zone limit is unlimited. An unlimited number
of entries may be set with 0 limit.
dpctl/ct-del-limits [dp] zone=zone[,zone]...
Deletes the connection tracking limit for zone. Multiple
zones may be specified with a comma-separated list.
dpctl/ct-get-limits [dp] [zone=zone[,zone]...]
Retrieves the maximum allowed number of connections and
current counts per-zone. If zone is given, only the
specified zone(s) are printed. If no zones are specified,
all the zone limits and counts are provided. The command
always displays the default zone limit.
DPDK COMMANDS
These commands manage DPDK components.
dpdk/lcore-list
Lists the DPDK lcores and their cpu affinity. When
RTE_MAX_LCORE lcores are registered, some OVS PMD threads
won't appear.
dpdk/log-list
Lists all DPDK components that emit logs and their logging
levels.
dpdk/log-set [spec]
Sets DPDK components logging level. Without any spec, sets
the logging level for all DPDK components to debug.
Otherwise, spec is a list of words separated by spaces: a
word can be either a logging level (emergency, alert,
critical, error, warning, notice, info or debug) or a
pattern matching DPDK components (see dpdk/log-list command
on ovs-appctl(8)) separated by a colon from the logging
level to apply.
dpdk/get-malloc-stats
Prints the heap information statistics about DPDK malloc.
dpdk/get-memzone-stats
Prints the reserved memory zones from DPDK.
DPIF-NETDEV COMMANDS
These commands are used to expose internal information (mostly
statistics) about the "dpif-netdev" userspace datapath. If there
is only one datapath (as is often the case, unless dpctl/ commands
are used), the dp argument can be omitted. By default the commands
present data for all pmd threads in the datapath. By specifying
the "-pmd Core" option one can filter the output for a single pmd
in the datapath.
dpif-netdev/pmd-stats-show [-pmd core] [dp]
Shows performance statistics for one or all pmd threads of
the datapath dp. The special thread "main" sums up the
statistics of every non pmd thread.
The sum of "phwol hits", "simple match hits", "emc hits",
"smc hits", "megaflow hits" and "miss" is the number of
packet lookups performed by the datapath. Beware that a
recirculated packet experiences one additional lookup per
recirculation, so there may be more lookups than forwarded
packets in the datapath.
The MFEX Opt hits displays the number of packets that are
processed by the optimized miniflow extract
implementations.
Cycles are counted using the TSC or similar facilities
(when available on the platform). The duration of one cycle
depends on the processing platform.
"idle cycles" refers to cycles spent in PMD iterations not
forwarding any any packets. "processing cycles" refers to
cycles spent in PMD iterations forwarding at least one
packet, including the cost for polling, processing and
transmitting said packets.
To reset these counters use dpif-netdev/pmd-stats-clear.
dpif-netdev/pmd-stats-clear [dp]
Resets to zero the per pmd thread performance numbers shown
by the dpif-netdev/pmd-stats-show and dpif-netdev/pmd-perf-
show commands. It will NOT reset datapath or bridge
statistics, only the values shown by the above commands.
dpif-netdev/pmd-perf-show [-nh] [-it iter_len] [-ms ms_len] [-pmd
core] [dp]
Shows detailed performance metrics for one or all pmds
threads of the user space datapath.
The collection of detailed statistics can be controlled by
a new configuration parameter "other_config:pmd-perf-
metrics". By default it is disabled. The run-time overhead,
when enabled, is in the order of 1%.
— used cycles
— forwared packets
— number of rx batches
— packets/rx batch
— max. vhostuser queue fill level
— number of upcalls
— cycles spent in upcalls
This raw recorded data is used threefold:
1. In histograms for each of the following metrics:
— cycles/iteration (logarithmic)
— packets/iteration (logarithmic)
— cycles/packet
— packets/batch
— max. vhostuser qlen (logarithmic)
— upcalls
— cycles/upcall (logarithmic) The histograms
bins are divided linear or logarithmic.
2. A cyclic history of the above metrics for 1024
iterations
3. A cyclic history of the cummulative/average values
per millisecond wall clock for the last 1024
milliseconds:
— number of iterations
— avg. cycles/iteration
— packets (Kpps)
— avg. packets/batch
— avg. max vhost qlen
— upcalls
— avg. cycles/upcall
The command options are:
-nh Suppress the histograms
-it iter_len
Display the last iter_len iteration stats
-ms ms_len
Display the last ms_len millisecond stats
The output always contains the following global PMD
statistics:
Time: 15:24:55.270
Measurement duration: 1.008 s
pmd thread numa_id 0 core_id 1:
Iterations: 572817 (1.76 us/it)
- Used TSC cycles: 2419034712 ( 99.9 % of total cycles)
- idle iterations: 486808 ( 15.9 % of used cycles)
- busy iterations: 86009 ( 84.1 % of used cycles)
Rx packets: 2399607 (2381 Kpps, 848 cycles/pkt)
Datapath passes: 3599415 (1.50 passes/pkt)
- PHWOL hits: 0 ( 0.0 %)
- MFEX Opt hits: 3570133 ( 99.2 %)
- Simple Match hits: 0 ( 0.0 %)
- EMC hits: 336472 ( 9.3 %)
- SMC hits: 0 ( 0.0 %)
- Megaflow hits: 3262943 ( 90.7 %, 1.00 subtbl lookups/hit)
- Upcalls: 0 ( 0.0 %, 0.0 us/upcall)
- Lost upcalls: 0 ( 0.0 %)
Tx packets: 2399607 (2381 Kpps)
Tx batches: 171400 (14.00 pkts/batch)
Here "Rx packets" actually reflects the number of packets
forwarded by the datapath. "Datapath passes" matches the
number of packet lookups as reported by the dpif-
netdev/pmd-stats-show command.
To reset the counters and start a new measurement use dpif-
netdev/pmd-stats-clear.
dpif-netdev/pmd-perf-log-set on|off [-b before] [-a after]
[-e|-ne] [-us usec] [-q qlen]
The userspace "netdev" datapath is able to supervise the
PMD performance metrics and detect iterations with
suspicious statistics according to the following criteria:
— The iteration lasts longer than usec microseconds
(default 250). This can be used to capture events
where a PMD is blocked or interrupted for such a
period of time that there is a risk for dropped
packets on any of its Rx queues.
— The max vhost qlen exceeds a threshold qlen (default
128). This can be used to infer virtio queue
overruns and dropped packets inside a VM, which are
not visible in OVS otherwise.
Such suspicious iterations can be logged together with
their iteration statistics in the ovs-vswitchd.log to be
able to correlate them to packet drop or other events
outside OVS.
The above command enables (on) or disables (off)
supervision and logging at run-time and can be used to
adjust the above thresholds for detecting suspicious
iterations. By default supervision and logging is disabled.
The command options are:
-b before
The number of iterations before the suspicious
iteration to be logged (default 5).
-a after
The number of iterations after the suspicious
iteration to be logged (default 5).
-e Extend logging interval if another suspicious
iteration is detected before logging occurs.
-ne Do not extend logging interval if another suspicious
iteration is detected before logging occurs
(default).
-q qlen
Suspicious vhost queue fill level threshold.
Increase this to 512 if the Qemu supports 1024
virtio queue length (default 128).
-us usec
Change the duration threshold for a suspicious
iteration (default 250 us).
Note: Logging of suspicious iterations itself consumes a
considerable amount of processing cycles of a PMD which may be
visible in the iteration history. In the worst case this can lead
OVS to detect another suspicious iteration caused by logging.
If more than 100 iterations around a suspicious iteration have
been logged once, OVS falls back to the safe default values (-b 5
-a 5 -ne) to avoid that logging itself continuously causes logging
of further suspicious iterations.
dpif-netdev/pmd-rxq-show [-pmd core] [dp]
For one or all pmd threads of the datapath dp show the list
of queue-ids with port names, which this thread polls.
dpif-netdev/pmd-rxq-rebalance [dp]
Reassigns rxqs to pmds in the datapath dp based on their
current usage.
dpif-netdev/bond-show [dp]
When "other_config:lb-output-action" is set to "true", the
userspace datapath handles the load balancing of bonds
directly instead of depending on flow recirculation (only
in balance-tcp mode).
When this is the case, the above command prints the load-
balancing information of the bonds configured in datapath
dp showing the interface associated with each bucket
(hash).
dpif-netdev/subtable-lookup-prio-get
Lists the DPCLS implementations or lookup functions that
are available as well as their priorities.
dpif-netdev/subtable-lookup-prio-set lookup_function prio
Sets the priority of a lookup function by name,
lookup_function, and priority, prio, which should be a
positive integer value. The highest priority lookup
function is used for classification.
The number of affected dpcls ports and subtables is
returned.
dpif-netdev/dpif-impl-get
Lists the DPIF implementations that are available.
dpif-netdev/dpif-impl-set dpif_impl
Sets the DPIF to be used to dpif_impl. By default
"dpif_scalar" is used.
dpif-netdev/miniflow-parser-get
Lists the miniflow extract implementations that are
available.
dpif-netdev/miniflow-parser-set [-pmd core] miniflow_impl
[study_cnt]
Sets the miniflow extract to miniflow_impl for a specified
PMD or all PMDs in the case where no value is specified.
By default "scalar" is used. study_cnt defaults to 128 and
indicates the number of packets that the "study" miniflow
implementation must parse before choosing an optimal
implementation.
DPIF-NETLINK COMMANDS
These commands are used to expose internal information of the
"dpif-netlink" kernel space datapath.
dpif-netlink/dispatch-mode
Displays the "dispatch-mode" for all datapaths.
NETDEV-DPDK COMMANDS
These commands manage DPDK related ports (type=dpdk*).
netdev-dpdk/set-admin-state [interface] up | down
Change the admin state for DPDK interface to up or down.
If interface is not specified, then it applies to all DPDK
ports.
netdev-dpdk/detach pci-address
Detaches device with corresponding pci-address from DPDK.
This command can be used to detach device if it wasn't
detached automatically after port deletion. Refer to the
documentation for details and instructions.
netdev-dpdk/get-mempool-info [interface]
Prints the debug information about memory pool used by DPDK
interface. If called without arguments, information of all
the available mempools will be printed. For additional
mempool statistics enable CONFIG_RTE_LIBRTE_MEMPOOL_DEBUG
while building DPDK.
ODP-EXECUTE COMMANDS
These commands manage the "odp-execute" component.
odp-execute/action-impl-show
Lists the actions implementations that are available and
highlights the currently enabled one.
odp-execute/action-impl-set action_impl
Sets the action implementation to any available
implementation. By default "scalar" is used.
DATAPATH DEBUGGING COMMANDS
These commands query and modify datapaths. They are are similar
to ovs-dpctl(8) commands. dpif/show has the additional
functionality, beyond dpctl/show of printing OpenFlow port
numbers. The other commands are redundant and will be removed in
a future release.
dpif/dump-dps
Prints the name of each configured datapath on a separate
line.
dpif/show
Prints a summary of configured datapaths, including
statistics and a list of connected ports. The port
information includes the OpenFlow port number, datapath
port number, and the type. (The local port is identified
as OpenFlow port 65534.)
dpif/dump-flows [-m] dp
Prints to the console all flow entries in datapath dp's
flow table. Without -m, output omits match fields that a
flow wildcards entirely; with -m output includes all
wildcarded fields.
This command is primarily useful for debugging Open
vSwitch. The flow table entries that it displays are not
OpenFlow flow entries. Instead, they are different and
considerably simpler flows maintained by the datapath
module. If you wish to see the OpenFlow flow entries, use
ovs-ofctl dump-flows.
dpif/del-flows dp
Deletes all flow entries from datapath dp's flow table and
underlying datapath implementation (e.g., kernel datapath
module).
This command is primarily useful for debugging Open
vSwitch. As discussed in dpif/dump-flows, these entries
are not OpenFlow flow entries.
OFPROTO COMMANDS
These commands manage the core OpenFlow switch implementation
(called ofproto).
ofproto/list
Lists the names of the running ofproto instances. These
are the names that may be used on ofproto/trace.
ofproto/trace [options] [dpname] odp_flow [packet]
ofproto/trace [options] bridge br_flow [packet]]
ofproto/trace-packet-out [options] [dpname] odp_flow [packet]
actions
ofproto/trace-packet-out [options] bridge br_flow [packet] actions
Traces the path of an imaginary packet through switch and
reports the path that it took. The initial treatment of
the packet varies based on the command:
• ofproto/trace looks the packet up in the OpenFlow
flow table, as if the packet had arrived on an
OpenFlow port.
• ofproto/trace-packet-out applies the specified
OpenFlow actions, as if the packet, flow, and
actions had been specified in an OpenFlow ``packet-
out'' request.
The packet's headers (e.g. source and destination) and
metadata (e.g. input port), together called its ``flow,''
are usually all that matter for the purpose of tracing a
packet. You can specify the flow in the following ways:
dpname odp_flow
odp_flow is a flow in the form printed by
ovs-dpctl(8)'s dump-flows command. If all of your
bridges have the same type, which is the common
case, then you can omit dpname, but if you have
bridges of different types (say, both ovs-netdev and
ovs-system), then you need to specify a dpname to
disambiguate.
bridge br_flow
br_flow is a flow in the form similar to that
accepted by ovs-ofctl(8)'s add-flow command. (This
is not an OpenFlow flow: besides other differences,
it never contains wildcards.) bridge names of the
bridge through which br_flow should be traced.
These commands support the following options:
--generate
Generate a packet from the flow (see below for more
information).
--l7 payload
--l7-len length
Accepted only with --generate (see below for more
information).
--consistent
Accepted by ofproto-trace-packet-out only. With
this option, the command rejects actions that are
inconsistent with the specified packet. (An example
of an inconsistency is attempting to strip the VLAN
tag from a packet that does not have a VLAN tag.)
Open vSwitch ignores most forms of inconsistency in
OpenFlow 1.0 and rejects inconsistencies in later
versions of OpenFlow. The option is necessary
because the command does not ordinarily imply a
particular OpenFlow version. One exception is that,
when actions includes an action that only OpenFlow
1.1 and later supports (such as push_vlan),
--consistent is automatically enabled.
--ct-next flags
When the traced flow triggers conntrack actions,
ofproto/trace will automatically trace the forked
packet processing pipeline with user specified
ct_state. This option sets the ct_state flags that
the conntrack module will report. The flags must be
a comma- or space-separated list of the following
connection tracking flags:
• trk: Include to indicate connection tracking
has taken place.
• new: Include to indicate a new flow.
• est: Include to indicate an established flow.
• rel: Include to indicate a related flow.
• rpl: Include to indicate a reply flow.
• inv: Include to indicate a connection entry
in a bad state.
• dnat: Include to indicate a packet whose
destination IP address has been changed.
• snat: Include to indicate a packet whose
source IP address has been changed.
When --ct-next is unspecified, or when there are
fewer --ct-next options than ct actions, the flags
default to trk,new.
Most commonly, one specifies only a flow, using one of the
forms above, but sometimes one might need to specify an
actual packet instead of just a flow:
Side effects.
Some actions have side effects. For example, the
normal action can update the MAC learning table, and
the learn action can change OpenFlow tables. The
trace commands only perform side effects when a
packet is specified. If you want side effects to
take place, then you must supply a packet.
(Output actions are obviously side effects too, but
the trace commands never execute them, even when one
specifies a packet.)
Incomplete information.
Most of the time, Open vSwitch can figure out
everything about the path of a packet using just the
flow, but in some special circumstances it needs to
look at parts of the packet that are not included in
the flow. When this is the case, and you do not
supply a packet, then a trace command will tell you
it needs a packet.
If you wish to include a packet as part of a trace
operation, there are two ways to do it:
--generate
This option, added to one of the ways to specify a
flow already described, causes Open vSwitch to
internally generate a packet with the flow described
and then to use that packet. If your goal is to
execute side effects, then --generate is the easiest
way to do it, but --generate is not a good way to
fill in incomplete information, because it generates
packets based on only the flow information, which
means that the packets really do not have any more
information than the flow.
By default, for protocols that allow arbitrary L7
payloads, the generated packet has 64 bytes of
payload. Use --l7-len to change the payload length,
or --l7 to specify the exact contents of the
payload.
packet This form supplies an explicit packet as a sequence
of hex digits. An Ethernet frame is at least 14
bytes long, so there must be at least 28 hex digits.
Obviously, it is inconvenient to type in the hex
digits by hand, so the ovs-pcap(1) and
ovs-tcpundump(1) utilities provide easier ways.
With this form, packet headers are extracted
directly from packet, so the odp_flow or br_flow
should specify only metadata. The metadata can be:
skb_priority
Packet QoS priority.
pkt_mark
Mark of the packet.
ct_state
Connection state of the packet.
ct_zone
Connection tracking zone for packet.
ct_mark
Connection mark of the packet.
ct_label
Connection label of the packet.
tun_id The tunnel ID on which the packet arrived.
in_port
The port on which the packet arrived.
The in_port value is kernel datapath port number for the
first format and OpenFlow port number for the second
format. The numbering of these two types of port usually
differs and there is no relationship.
Usage examples:
Trace an unicast ICMP echo request on ingress port 1 to
destination MAC 00:00:5E:00:53:01
ofproto/trace br in_port=1,icmp,icmp_type=8,\
dl_dst=00:00:5E:00:53:01
Trace an unicast ICMP echo reply on ingress port 1 to
destination MAC 00:00:5E:00:53:01
ofproto/trace br in_port=1,icmp,icmp_type=0,\
dl_dst=00:00:5E:00:53:01
Trace an ARP request on ingress port 1
ofproto/trace br in_port=1,arp,arp_op=1
Trace an ARP reply on ingress port 1
ofproto/trace br in_port=1,arp,arp_op=2
VLOG COMMANDS
These commands manage ovs-vswitchd's logging settings.
vlog/set [spec]
Sets logging levels. Without any spec, sets the log level
for every module and destination to dbg. Otherwise, spec
is a list of words separated by spaces or commas or colons,
up to one from each category below:
• A valid module name, as displayed by the vlog/list
command on ovs-appctl(8), limits the log level
change to the specified module.
• syslog, console, or file, to limit the log level
change to only to the system log, to the console, or
to a file, respectively.
On Windows platform, syslog is accepted as a word
and is only useful along with the --syslog-target
option (the word has no effect otherwise).
• off, emer, err, warn, info, or dbg, to control the
log level. Messages of the given severity or higher
will be logged, and messages of lower severity will
be filtered out. off filters out all messages. See
ovs-appctl(8) for a definition of each log level.
Case is not significant within spec.
Regardless of the log levels set for file, logging to a
file will not take place unless ovs-vswitchd was invoked
with the --log-file option.
For compatibility with older versions of OVS, any is
accepted as a word but has no effect.
vlog/set PATTERN:destination:pattern
Sets the log pattern for destination to pattern. Refer to
ovs-appctl(8) for a description of the valid syntax for
pattern.
vlog/list
Lists the supported logging modules and their current
levels.
vlog/list-pattern
Lists logging patterns used for each destination.
vlog/close
Causes ovs-vswitchd to close its log file, if it is open.
(Use vlog/reopen to reopen it later.)
vlog/reopen
Causes ovs-vswitchd to close its log file, if it is open,
and then reopen it. (This is useful after rotating log
files, to cause a new log file to be used.)
This has no effect unless ovs-vswitchd was invoked with the
--log-file option.
vlog/disable-rate-limit [module]...
vlog/enable-rate-limit [module]...
By default, ovs-vswitchd limits the rate at which certain
messages can be logged. When a message would appear more
frequently than the limit, it is suppressed. This saves
disk space, makes logs easier to read, and speeds up
execution, but occasionally troubleshooting requires more
detail. Therefore, vlog/disable-rate-limit allows rate
limits to be disabled at the level of an individual log
module. Specify one or more module names, as displayed by
the vlog/list command. Specifying either no module names
at all or the keyword any disables rate limits for every
log module.
The vlog/enable-rate-limit command, whose syntax is the
same as vlog/disable-rate-limit, can be used to re-enable a
rate limit that was previously disabled.
MEMORY COMMANDS
These commands report memory usage.
memory/show
Displays some basic statistics about ovs-vswitchd's memory
usage. ovs-vswitchd also logs this information soon after
startup and periodically as its memory consumption grows.
COVERAGE COMMANDS
These commands manage ovs-vswitchd's ``coverage counters,'' which
count the number of times particular events occur during a
daemon's runtime. In addition to these commands, ovs-vswitchd
automatically logs coverage counter values, at INFO level, when it
detects that the daemon's main loop takes unusually long to run.
Coverage counters are useful mainly for performance analysis and
debugging.
coverage/show
Displays the averaged per-second rates for the last few
seconds, the last minute and the last hour, and the total
counts of all of the coverage counters.
coverage/read-counter counter
Displays the total count for the given coverage counter.
OPENVSWITCH TUNNELING COMMANDS
These commands query and modify OVS tunnel components.
ovs/route/add ip/plen output_bridge [gw] [pkt_mark=mark]
[src=src_ip]
Adds ip/plen route to vswitchd routing table. output_bridge
needs to be OVS bridge name. This command is useful if OVS
cached routes does not look right.
ovs/route/show
Print all routes in OVS routing table, This includes routes
cached from system routing table and user configured
routes.
ovs/route/del ip/plen [pkt_mark=mark]
Delete ip/plen route from OVS routing table.
tnl/neigh/show
tnl/arp/show
OVS builds ARP cache by snooping are messages. This command
shows ARP cache table.
tnl/neigh/set bridge ip mac
tnl/arp/set bridge ip mac
Adds or modifies an ARP cache entry in bridge, mapping ip
to mac.
tnl/neigh/flush
tnl/arp/flush
Flush ARP table.
tnl/neigh/aging [seconds]
tnl/arp/aging [seconds]
Changes the aging time. The accepted values of seconds are
between 1 and 3600. The new entries will get the value as
specified in seconds. For the existing entries, the aging
time is updated only if the current expiration is greater
than seconds.
If used without arguments, it prints the current aging
value.
tnl/egress_port_range [num1] [num2]
Set range for UDP source port used for UDP based Tunnels.
For example VxLAN. If case of zero arguments this command
prints current range in use.
This section documents aspects of OpenFlow for which the OpenFlow
specification requires documentation.
Packet buffering.
The OpenFlow specification, version 1.2, says:
Switches that implement buffering are expected to expose,
through documentation, both the amount of available
buffering, and the length of time before buffers may be
reused.
Open vSwitch does not maintains any packet buffers.
Bundle lifetime
The OpenFlow specification, version 1.4, says:
If the switch does not receive any OFPT_BUNDLE_CONTROL or
OFPT_BUNDLE_ADD_MESSAGE message for an opened bundle_id for
a switch defined time greater than 1s, it may send an
ofp_error_msg with OFPET_BUNDLE_FAILED type and
OFPBFC_TIMEOUT code. If the switch does not receive any
new message in a bundle apart from echo request and replies
for a switch defined time greater than 1s, it may send an
ofp_error_msg with OFPET_BUNDLE_FAILED type and
OFPBFC_TIMEOUT code.
Open vSwitch implements default idle bundle lifetime of 10
seconds. (This is configurable via other-config:bundle-idle-
timeout in the Open_vSwitch table. See ovs-vswitchd.conf.db(5) for
details.)
We believe these limits to be accurate as of this writing. These
limits assume the use of the Linux kernel datapath.
• ovs-vswitchd started through ovs-ctl(8) provides a limit of
65535 file descriptors. The limits on the number of
bridges and ports is decided by the availability of file
descriptors. With the Linux kernel datapath, creation of a
single bridge consumes three file descriptors and each port
consumes one additional file descriptor. Other platforms
may have different limitations.
• 8,192 MAC learning entries per bridge, by default. (This
is configurable via other-config:mac-table-size in the
Bridge table. See ovs-vswitchd.conf.db(5) for details.)
• Kernel flows are limited only by memory available to the
kernel. Performance will degrade beyond 1,048,576 kernel
flows per bridge with a 32-bit kernel, beyond 262,144 with
a 64-bit kernel. (ovs-vswitchd should never install
anywhere near that many flows.)
• OpenFlow flows are limited only by available memory.
Performance is linear in the number of unique wildcard
patterns. That is, an OpenFlow table that contains many
flows that all match on the same fields in the same way has
a constant-time lookup, but a table that contains many
flows that match on different fields requires lookup time
linear in the number of flows.
• 255 ports per bridge participating in 802.1D Spanning Tree
Protocol.
• 32 mirrors per bridge.
• 15 bytes for the name of a port, for ports implemented in
the Linux kernel. Ports implemented in userspace, such as
patch ports, do not have an arbitrary length limitation.
OpenFlow also limit port names to 15 bytes.
ovs-appctl(8), ovsdb-server(1).
This page is part of the Open vSwitch (a distributed virtual
multilayer switch) project. Information about the project can be
found at ⟨http://openvswitch.org/⟩. If you have a bug report for
this manual page, send it to bugs@openvswitch.org. This page was
obtained from the project's upstream Git repository
⟨https://github.com/openvswitch/ovs.git⟩ on 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-07-31.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Open vSwitch 3.5.90 ovs-vswitchd(8)
Pages that refer to this page: ovs-pcap(1), ovs-tcpundump(1), ovn-architecture(7), ovsdb(7), ovn-controller(8), ovs-appctl(8), ovs-ctl(8), ovs-dpctl(8), ovs-l3ping(8), ovs-ofctl(8), ovs-tcpdump(8), ovs-test(8), ovs-vlan-test(8), ovs-vsctl(8)
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